[{"isotope":"H-1","atomic_number":1,"element_symbol":"H","nist_symbol":"H","mass_number":1,"neutrons":0,"relative_atomic_mass":1.00782503223,"relative_atomic_mass_uncertainty":9e-11,"mass_estimated":false,"natural_abundance":0.999885,"natural_abundance_uncertainty":0.00007,"naturally_occurring":true,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-2","atomic_number":1,"element_symbol":"H","nist_symbol":"D","mass_number":2,"neutrons":1,"relative_atomic_mass":2.01410177812,"relative_atomic_mass_uncertainty":1.2e-10,"mass_estimated":false,"natural_abundance":0.000115,"natural_abundance_uncertainty":0.00007,"naturally_occurring":true,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-3","atomic_number":1,"element_symbol":"H","nist_symbol":"T","mass_number":3,"neutrons":2,"relative_atomic_mass":3.0160492779,"relative_atomic_mass_uncertainty":2.4e-9,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-4","atomic_number":1,"element_symbol":"H","nist_symbol":"H","mass_number":4,"neutrons":3,"relative_atomic_mass":4.02643,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-5","atomic_number":1,"element_symbol":"H","nist_symbol":"H","mass_number":5,"neutrons":4,"relative_atomic_mass":5.035311,"relative_atomic_mass_uncertainty":0.000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-6","atomic_number":1,"element_symbol":"H","nist_symbol":"H","mass_number":6,"neutrons":5,"relative_atomic_mass":6.04496,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"H-7","atomic_number":1,"element_symbol":"H","nist_symbol":"H","mass_number":7,"neutrons":6,"relative_atomic_mass":7.0527,"relative_atomic_mass_uncertainty":0.0011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[1.00784,1.00811]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"He-3","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":3,"neutrons":1,"relative_atomic_mass":3.0160293201,"relative_atomic_mass_uncertainty":2.5e-9,"mass_estimated":false,"natural_abundance":0.00000134,"natural_abundance_uncertainty":3e-8,"naturally_occurring":true,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-4","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":4,"neutrons":2,"relative_atomic_mass":4.00260325413,"relative_atomic_mass_uncertainty":6e-11,"mass_estimated":false,"natural_abundance":0.99999866,"natural_abundance_uncertainty":3e-8,"naturally_occurring":true,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-5","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":5,"neutrons":3,"relative_atomic_mass":5.012057,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-6","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":6,"neutrons":4,"relative_atomic_mass":6.018885891,"relative_atomic_mass_uncertainty":5.7e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-7","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":7,"neutrons":5,"relative_atomic_mass":7.0279907,"relative_atomic_mass_uncertainty":0.0000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-8","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":8,"neutrons":6,"relative_atomic_mass":8.03393439,"relative_atomic_mass_uncertainty":9.5e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-9","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":9,"neutrons":7,"relative_atomic_mass":9.043946,"relative_atomic_mass_uncertainty":0.00005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"He-10","atomic_number":2,"element_symbol":"He","nist_symbol":"He","mass_number":10,"neutrons":8,"relative_atomic_mass":10.05279,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"4.002602(2)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Li-3","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":3,"neutrons":0,"relative_atomic_mass":3.0308,"relative_atomic_mass_uncertainty":0.0021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-4","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":4,"neutrons":1,"relative_atomic_mass":4.02719,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-5","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":5,"neutrons":2,"relative_atomic_mass":5.012538,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-6","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":6,"neutrons":3,"relative_atomic_mass":6.0151228874,"relative_atomic_mass_uncertainty":1.6e-9,"mass_estimated":false,"natural_abundance":0.0759,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-7","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":7,"neutrons":4,"relative_atomic_mass":7.0160034366,"relative_atomic_mass_uncertainty":4.5e-9,"mass_estimated":false,"natural_abundance":0.9241,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-8","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":8,"neutrons":5,"relative_atomic_mass":8.022486246,"relative_atomic_mass_uncertainty":5e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-9","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":9,"neutrons":6,"relative_atomic_mass":9.02679019,"relative_atomic_mass_uncertainty":2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-10","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":10,"neutrons":7,"relative_atomic_mass":10.035483,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-11","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":11,"neutrons":8,"relative_atomic_mass":11.04372358,"relative_atomic_mass_uncertainty":6.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-12","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":12,"neutrons":9,"relative_atomic_mass":12.052517,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Li-13","atomic_number":3,"element_symbol":"Li","nist_symbol":"Li","mass_number":13,"neutrons":10,"relative_atomic_mass":13.06263,"relative_atomic_mass_uncertainty":0.00038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[6.938,6.997]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Be-5","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":5,"neutrons":1,"relative_atomic_mass":5.0399,"relative_atomic_mass_uncertainty":0.0022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-6","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":6,"neutrons":2,"relative_atomic_mass":6.0197264,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-7","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":7,"neutrons":3,"relative_atomic_mass":7.016928717,"relative_atomic_mass_uncertainty":7.6e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-8","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":8,"neutrons":4,"relative_atomic_mass":8.005305102,"relative_atomic_mass_uncertainty":3.7e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-9","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":9,"neutrons":5,"relative_atomic_mass":9.012183065,"relative_atomic_mass_uncertainty":8.2e-8,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-10","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":10,"neutrons":6,"relative_atomic_mass":10.013534695,"relative_atomic_mass_uncertainty":8.6e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-11","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":11,"neutrons":7,"relative_atomic_mass":11.02166108,"relative_atomic_mass_uncertainty":2.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-12","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":12,"neutrons":8,"relative_atomic_mass":12.0269221,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-13","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":13,"neutrons":9,"relative_atomic_mass":13.036135,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-14","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":14,"neutrons":10,"relative_atomic_mass":14.04289,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-15","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":15,"neutrons":11,"relative_atomic_mass":15.05342,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"Be-16","atomic_number":4,"element_symbol":"Be","nist_symbol":"Be","mass_number":16,"neutrons":12,"relative_atomic_mass":16.06167,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"9.0121831(5)","notes":null},{"isotope":"B-6","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":6,"neutrons":1,"relative_atomic_mass":6.0508,"relative_atomic_mass_uncertainty":0.0022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-7","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":7,"neutrons":2,"relative_atomic_mass":7.029712,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-8","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":8,"neutrons":3,"relative_atomic_mass":8.0246073,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-9","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":9,"neutrons":4,"relative_atomic_mass":9.01332965,"relative_atomic_mass_uncertainty":9.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-10","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":10,"neutrons":5,"relative_atomic_mass":10.01293695,"relative_atomic_mass_uncertainty":4.1e-7,"mass_estimated":false,"natural_abundance":0.199,"natural_abundance_uncertainty":0.007,"naturally_occurring":true,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-11","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":11,"neutrons":6,"relative_atomic_mass":11.00930536,"relative_atomic_mass_uncertainty":4.5e-7,"mass_estimated":false,"natural_abundance":0.801,"natural_abundance_uncertainty":0.007,"naturally_occurring":true,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-12","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":12,"neutrons":7,"relative_atomic_mass":12.0143527,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-13","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":13,"neutrons":8,"relative_atomic_mass":13.0177802,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-14","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":14,"neutrons":9,"relative_atomic_mass":14.025404,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-15","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":15,"neutrons":10,"relative_atomic_mass":15.031088,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-16","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":16,"neutrons":11,"relative_atomic_mass":16.039842,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-17","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":17,"neutrons":12,"relative_atomic_mass":17.04699,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-18","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":18,"neutrons":13,"relative_atomic_mass":18.05566,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-19","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":19,"neutrons":14,"relative_atomic_mass":19.0631,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-20","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":20,"neutrons":15,"relative_atomic_mass":20.07207,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"B-21","atomic_number":5,"element_symbol":"B","nist_symbol":"B","mass_number":21,"neutrons":16,"relative_atomic_mass":21.08129,"relative_atomic_mass_uncertainty":0.00097,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[10.806,10.821]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"C-8","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":8,"neutrons":2,"relative_atomic_mass":8.037643,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-9","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":9,"neutrons":3,"relative_atomic_mass":9.0310372,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-10","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":10,"neutrons":4,"relative_atomic_mass":10.01685331,"relative_atomic_mass_uncertainty":4.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-11","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":11,"neutrons":5,"relative_atomic_mass":11.0114336,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-12","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":12,"neutrons":6,"relative_atomic_mass":12,"relative_atomic_mass_uncertainty":0,"mass_estimated":false,"natural_abundance":0.9893,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-13","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":13,"neutrons":7,"relative_atomic_mass":13.00335483507,"relative_atomic_mass_uncertainty":2.3e-10,"mass_estimated":false,"natural_abundance":0.0107,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-14","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":14,"neutrons":8,"relative_atomic_mass":14.0032419884,"relative_atomic_mass_uncertainty":4e-9,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-15","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":15,"neutrons":9,"relative_atomic_mass":15.01059926,"relative_atomic_mass_uncertainty":8.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-16","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":16,"neutrons":10,"relative_atomic_mass":16.0147013,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-17","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":17,"neutrons":11,"relative_atomic_mass":17.022577,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-18","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":18,"neutrons":12,"relative_atomic_mass":18.026751,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-19","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":19,"neutrons":13,"relative_atomic_mass":19.0348,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-20","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":20,"neutrons":14,"relative_atomic_mass":20.04032,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-21","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":21,"neutrons":15,"relative_atomic_mass":21.049,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-22","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":22,"neutrons":16,"relative_atomic_mass":22.05753,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"C-23","atomic_number":6,"element_symbol":"C","nist_symbol":"C","mass_number":23,"neutrons":17,"relative_atomic_mass":23.0689,"relative_atomic_mass_uncertainty":0.0011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[12.0096,12.0116]","notes":null},{"isotope":"N-10","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":10,"neutrons":3,"relative_atomic_mass":10.04165,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-11","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":11,"neutrons":4,"relative_atomic_mass":11.026091,"relative_atomic_mass_uncertainty":0.00005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-12","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":12,"neutrons":5,"relative_atomic_mass":12.0186132,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-13","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":13,"neutrons":6,"relative_atomic_mass":13.00573861,"relative_atomic_mass_uncertainty":2.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-14","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":14,"neutrons":7,"relative_atomic_mass":14.00307400443,"relative_atomic_mass_uncertainty":2e-10,"mass_estimated":false,"natural_abundance":0.99636,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-15","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":15,"neutrons":8,"relative_atomic_mass":15.00010889888,"relative_atomic_mass_uncertainty":6.4e-10,"mass_estimated":false,"natural_abundance":0.00364,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-16","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":16,"neutrons":9,"relative_atomic_mass":16.0061019,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-17","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":17,"neutrons":10,"relative_atomic_mass":17.008449,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-18","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":18,"neutrons":11,"relative_atomic_mass":18.014078,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-19","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":19,"neutrons":12,"relative_atomic_mass":19.017022,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-20","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":20,"neutrons":13,"relative_atomic_mass":20.023366,"relative_atomic_mass_uncertainty":0.00006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-21","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":21,"neutrons":14,"relative_atomic_mass":21.02711,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-22","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":22,"neutrons":15,"relative_atomic_mass":22.03439,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-23","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":23,"neutrons":16,"relative_atomic_mass":23.04114,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-24","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":24,"neutrons":17,"relative_atomic_mass":24.05039,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"N-25","atomic_number":7,"element_symbol":"N","nist_symbol":"N","mass_number":25,"neutrons":18,"relative_atomic_mass":25.0601,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[14.00643,14.00728]","notes":null},{"isotope":"O-12","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":12,"neutrons":4,"relative_atomic_mass":12.034262,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-13","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":13,"neutrons":5,"relative_atomic_mass":13.024815,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-14","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":14,"neutrons":6,"relative_atomic_mass":14.00859636,"relative_atomic_mass_uncertainty":1.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-15","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":15,"neutrons":7,"relative_atomic_mass":15.00306562,"relative_atomic_mass_uncertainty":5.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-16","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":16,"neutrons":8,"relative_atomic_mass":15.99491461957,"relative_atomic_mass_uncertainty":1.7e-10,"mass_estimated":false,"natural_abundance":0.99757,"natural_abundance_uncertainty":0.00016,"naturally_occurring":true,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-17","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":17,"neutrons":9,"relative_atomic_mass":16.9991317565,"relative_atomic_mass_uncertainty":6.9e-10,"mass_estimated":false,"natural_abundance":0.00038,"natural_abundance_uncertainty":0.00001,"naturally_occurring":true,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-18","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":18,"neutrons":10,"relative_atomic_mass":17.99915961286,"relative_atomic_mass_uncertainty":7.6e-10,"mass_estimated":false,"natural_abundance":0.00205,"natural_abundance_uncertainty":0.00014,"naturally_occurring":true,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-19","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":19,"neutrons":11,"relative_atomic_mass":19.003578,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-20","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":20,"neutrons":12,"relative_atomic_mass":20.00407535,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-21","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":21,"neutrons":13,"relative_atomic_mass":21.008655,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-22","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":22,"neutrons":14,"relative_atomic_mass":22.009966,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-23","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":23,"neutrons":15,"relative_atomic_mass":23.015696,"relative_atomic_mass_uncertainty":0.000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-24","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":24,"neutrons":16,"relative_atomic_mass":24.01986,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-25","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":25,"neutrons":17,"relative_atomic_mass":25.02936,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-26","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":26,"neutrons":18,"relative_atomic_mass":26.03729,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-27","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":27,"neutrons":19,"relative_atomic_mass":27.04772,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"O-28","atomic_number":8,"element_symbol":"O","nist_symbol":"O","mass_number":28,"neutrons":20,"relative_atomic_mass":28.05591,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[15.99903,15.99977]","notes":null},{"isotope":"F-14","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":14,"neutrons":5,"relative_atomic_mass":14.034315,"relative_atomic_mass_uncertainty":0.000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-15","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":15,"neutrons":6,"relative_atomic_mass":15.018043,"relative_atomic_mass_uncertainty":0.000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-16","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":16,"neutrons":7,"relative_atomic_mass":16.0114657,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-17","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":17,"neutrons":8,"relative_atomic_mass":17.00209524,"relative_atomic_mass_uncertainty":2.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-18","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":18,"neutrons":9,"relative_atomic_mass":18.00093733,"relative_atomic_mass_uncertainty":5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-19","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":19,"neutrons":10,"relative_atomic_mass":18.99840316273,"relative_atomic_mass_uncertainty":9.2e-10,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-20","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":20,"neutrons":11,"relative_atomic_mass":19.999981252,"relative_atomic_mass_uncertainty":3.1e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-21","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":21,"neutrons":12,"relative_atomic_mass":20.9999489,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-22","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":22,"neutrons":13,"relative_atomic_mass":22.002999,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-23","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":23,"neutrons":14,"relative_atomic_mass":23.003557,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-24","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":24,"neutrons":15,"relative_atomic_mass":24.008115,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-25","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":25,"neutrons":16,"relative_atomic_mass":25.012199,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-26","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":26,"neutrons":17,"relative_atomic_mass":26.020038,"relative_atomic_mass_uncertainty":0.000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-27","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":27,"neutrons":18,"relative_atomic_mass":27.02644,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-28","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":28,"neutrons":19,"relative_atomic_mass":28.03534,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-29","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":29,"neutrons":20,"relative_atomic_mass":29.04254,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-30","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":30,"neutrons":21,"relative_atomic_mass":30.05165,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"F-31","atomic_number":9,"element_symbol":"F","nist_symbol":"F","mass_number":31,"neutrons":22,"relative_atomic_mass":31.05971,"relative_atomic_mass_uncertainty":0.00056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"18.998403163(6)","notes":null},{"isotope":"Ne-16","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":16,"neutrons":6,"relative_atomic_mass":16.02575,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-17","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":17,"neutrons":7,"relative_atomic_mass":17.01771396,"relative_atomic_mass_uncertainty":3.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-18","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":18,"neutrons":8,"relative_atomic_mass":18.0057087,"relative_atomic_mass_uncertainty":3.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-19","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":19,"neutrons":9,"relative_atomic_mass":19.00188091,"relative_atomic_mass_uncertainty":1.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-20","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":20,"neutrons":10,"relative_atomic_mass":19.9924401762,"relative_atomic_mass_uncertainty":1.7e-9,"mass_estimated":false,"natural_abundance":0.9048,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-21","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":21,"neutrons":11,"relative_atomic_mass":20.993846685,"relative_atomic_mass_uncertainty":4.1e-8,"mass_estimated":false,"natural_abundance":0.0027,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-22","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":22,"neutrons":12,"relative_atomic_mass":21.991385114,"relative_atomic_mass_uncertainty":1.8e-8,"mass_estimated":false,"natural_abundance":0.0925,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-23","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":23,"neutrons":13,"relative_atomic_mass":22.99446691,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-24","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":24,"neutrons":14,"relative_atomic_mass":23.99361065,"relative_atomic_mass_uncertainty":5.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-25","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":25,"neutrons":15,"relative_atomic_mass":24.997789,"relative_atomic_mass_uncertainty":0.000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-26","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":26,"neutrons":16,"relative_atomic_mass":26.000515,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-27","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":27,"neutrons":17,"relative_atomic_mass":27.007553,"relative_atomic_mass_uncertainty":0.00007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-28","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":28,"neutrons":18,"relative_atomic_mass":28.01212,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-29","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":29,"neutrons":19,"relative_atomic_mass":29.01975,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-30","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":30,"neutrons":20,"relative_atomic_mass":30.02473,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-31","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":31,"neutrons":21,"relative_atomic_mass":31.0331,"relative_atomic_mass_uncertainty":0.0017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-32","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":32,"neutrons":22,"relative_atomic_mass":32.03972,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-33","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":33,"neutrons":23,"relative_atomic_mass":33.04938,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Ne-34","atomic_number":10,"element_symbol":"Ne","nist_symbol":"Ne","mass_number":34,"neutrons":24,"relative_atomic_mass":34.05673,"relative_atomic_mass_uncertainty":0.00055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"20.1797(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Na-18","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":18,"neutrons":7,"relative_atomic_mass":18.02688,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-19","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":19,"neutrons":8,"relative_atomic_mass":19.01388,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-20","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":20,"neutrons":9,"relative_atomic_mass":20.0073544,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-21","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":21,"neutrons":10,"relative_atomic_mass":20.99765469,"relative_atomic_mass_uncertainty":3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-22","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":22,"neutrons":11,"relative_atomic_mass":21.99443741,"relative_atomic_mass_uncertainty":1.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-23","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":23,"neutrons":12,"relative_atomic_mass":22.989769282,"relative_atomic_mass_uncertainty":1.9e-9,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-24","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":24,"neutrons":13,"relative_atomic_mass":23.99096295,"relative_atomic_mass_uncertainty":3.8e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-25","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":25,"neutrons":14,"relative_atomic_mass":24.989954,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-26","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":26,"neutrons":15,"relative_atomic_mass":25.9926346,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-27","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":27,"neutrons":16,"relative_atomic_mass":26.9940765,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-28","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":28,"neutrons":17,"relative_atomic_mass":27.998939,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-29","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":29,"neutrons":18,"relative_atomic_mass":29.0028771,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-30","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":30,"neutrons":19,"relative_atomic_mass":30.0090979,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-31","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":31,"neutrons":20,"relative_atomic_mass":31.013163,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-32","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":32,"neutrons":21,"relative_atomic_mass":32.02019,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-33","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":33,"neutrons":22,"relative_atomic_mass":33.02573,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-34","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":34,"neutrons":23,"relative_atomic_mass":34.03359,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-35","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":35,"neutrons":24,"relative_atomic_mass":35.04062,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-36","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":36,"neutrons":25,"relative_atomic_mass":36.04929,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Na-37","atomic_number":11,"element_symbol":"Na","nist_symbol":"Na","mass_number":37,"neutrons":26,"relative_atomic_mass":37.05705,"relative_atomic_mass_uncertainty":0.00065,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"22.98976928(2)","notes":null},{"isotope":"Mg-19","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":19,"neutrons":7,"relative_atomic_mass":19.034169,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-20","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":20,"neutrons":8,"relative_atomic_mass":20.01885,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-21","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":21,"neutrons":9,"relative_atomic_mass":21.011716,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-22","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":22,"neutrons":10,"relative_atomic_mass":21.99957065,"relative_atomic_mass_uncertainty":3.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-23","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":23,"neutrons":11,"relative_atomic_mass":22.99412421,"relative_atomic_mass_uncertainty":7.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-24","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":24,"neutrons":12,"relative_atomic_mass":23.985041697,"relative_atomic_mass_uncertainty":1.4e-8,"mass_estimated":false,"natural_abundance":0.7899,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-25","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":25,"neutrons":13,"relative_atomic_mass":24.985836976,"relative_atomic_mass_uncertainty":5e-8,"mass_estimated":false,"natural_abundance":0.1,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-26","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":26,"neutrons":14,"relative_atomic_mass":25.982592968,"relative_atomic_mass_uncertainty":3.1e-8,"mass_estimated":false,"natural_abundance":0.1101,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-27","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":27,"neutrons":15,"relative_atomic_mass":26.984340624,"relative_atomic_mass_uncertainty":5.3e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-28","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":28,"neutrons":16,"relative_atomic_mass":27.9838767,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-29","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":29,"neutrons":17,"relative_atomic_mass":28.988617,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-30","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":30,"neutrons":18,"relative_atomic_mass":29.9904629,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-31","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":31,"neutrons":19,"relative_atomic_mass":30.996648,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-32","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":32,"neutrons":20,"relative_atomic_mass":31.9991102,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-33","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":33,"neutrons":21,"relative_atomic_mass":33.0053271,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-34","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":34,"neutrons":22,"relative_atomic_mass":34.008935,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-35","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":35,"neutrons":23,"relative_atomic_mass":35.01679,"relative_atomic_mass_uncertainty":0.00019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-36","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":36,"neutrons":24,"relative_atomic_mass":36.02188,"relative_atomic_mass_uncertainty":0.00049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-37","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":37,"neutrons":25,"relative_atomic_mass":37.03037,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-38","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":38,"neutrons":26,"relative_atomic_mass":38.03658,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-39","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":39,"neutrons":27,"relative_atomic_mass":39.04538,"relative_atomic_mass_uncertainty":0.00055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Mg-40","atomic_number":12,"element_symbol":"Mg","nist_symbol":"Mg","mass_number":40,"neutrons":28,"relative_atomic_mass":40.05218,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[24.304,24.307]","notes":null},{"isotope":"Al-21","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":21,"neutrons":8,"relative_atomic_mass":21.02897,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-22","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":22,"neutrons":9,"relative_atomic_mass":22.01954,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-23","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":23,"neutrons":10,"relative_atomic_mass":23.00724435,"relative_atomic_mass_uncertainty":3.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-24","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":24,"neutrons":11,"relative_atomic_mass":23.9999489,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-25","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":25,"neutrons":12,"relative_atomic_mass":24.9904281,"relative_atomic_mass_uncertainty":5.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-26","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":26,"neutrons":13,"relative_atomic_mass":25.986891904,"relative_atomic_mass_uncertainty":6.9e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-27","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":27,"neutrons":14,"relative_atomic_mass":26.98153853,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-28","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":28,"neutrons":15,"relative_atomic_mass":27.98191021,"relative_atomic_mass_uncertainty":1.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-29","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":29,"neutrons":16,"relative_atomic_mass":28.9804565,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-30","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":30,"neutrons":17,"relative_atomic_mass":29.98296,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-31","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":31,"neutrons":18,"relative_atomic_mass":30.983945,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-32","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":32,"neutrons":19,"relative_atomic_mass":31.988085,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-33","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":33,"neutrons":20,"relative_atomic_mass":32.990909,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-34","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":34,"neutrons":21,"relative_atomic_mass":33.996705,"relative_atomic_mass_uncertainty":0.000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-35","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":35,"neutrons":22,"relative_atomic_mass":34.999764,"relative_atomic_mass_uncertainty":0.000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-36","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":36,"neutrons":23,"relative_atomic_mass":36.00639,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-37","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":37,"neutrons":24,"relative_atomic_mass":37.01053,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-38","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":38,"neutrons":25,"relative_atomic_mass":38.0174,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-39","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":39,"neutrons":26,"relative_atomic_mass":39.02254,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-40","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":40,"neutrons":27,"relative_atomic_mass":40.03003,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-41","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":41,"neutrons":28,"relative_atomic_mass":41.03638,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-42","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":42,"neutrons":29,"relative_atomic_mass":42.04384,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Al-43","atomic_number":13,"element_symbol":"Al","nist_symbol":"Al","mass_number":43,"neutrons":30,"relative_atomic_mass":43.05147,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"26.9815385(7)","notes":null},{"isotope":"Si-22","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":22,"neutrons":8,"relative_atomic_mass":22.03579,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-23","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":23,"neutrons":9,"relative_atomic_mass":23.02544,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-24","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":24,"neutrons":10,"relative_atomic_mass":24.011535,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-25","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":25,"neutrons":11,"relative_atomic_mass":25.004109,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-26","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":26,"neutrons":12,"relative_atomic_mass":25.99233384,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-27","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":27,"neutrons":13,"relative_atomic_mass":26.98670481,"relative_atomic_mass_uncertainty":1.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-28","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":28,"neutrons":14,"relative_atomic_mass":27.97692653465,"relative_atomic_mass_uncertainty":4.4e-10,"mass_estimated":false,"natural_abundance":0.92223,"natural_abundance_uncertainty":0.00019,"naturally_occurring":true,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-29","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":29,"neutrons":15,"relative_atomic_mass":28.9764946649,"relative_atomic_mass_uncertainty":5.2e-10,"mass_estimated":false,"natural_abundance":0.04685,"natural_abundance_uncertainty":0.00008,"naturally_occurring":true,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-30","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":30,"neutrons":16,"relative_atomic_mass":29.973770136,"relative_atomic_mass_uncertainty":2.3e-8,"mass_estimated":false,"natural_abundance":0.03092,"natural_abundance_uncertainty":0.00011,"naturally_occurring":true,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-31","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":31,"neutrons":17,"relative_atomic_mass":30.975363194,"relative_atomic_mass_uncertainty":4.6e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-32","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":32,"neutrons":18,"relative_atomic_mass":31.97415154,"relative_atomic_mass_uncertainty":3.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-33","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":33,"neutrons":19,"relative_atomic_mass":32.97797696,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-34","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":34,"neutrons":20,"relative_atomic_mass":33.978576,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-35","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":35,"neutrons":21,"relative_atomic_mass":34.984583,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-36","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":36,"neutrons":22,"relative_atomic_mass":35.986695,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-37","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":37,"neutrons":23,"relative_atomic_mass":36.992921,"relative_atomic_mass_uncertainty":0.000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-38","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":38,"neutrons":24,"relative_atomic_mass":37.995523,"relative_atomic_mass_uncertainty":0.000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-39","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":39,"neutrons":25,"relative_atomic_mass":39.002491,"relative_atomic_mass_uncertainty":0.000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-40","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":40,"neutrons":26,"relative_atomic_mass":40.00583,"relative_atomic_mass_uncertainty":0.00025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-41","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":41,"neutrons":27,"relative_atomic_mass":41.01301,"relative_atomic_mass_uncertainty":0.0004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-42","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":42,"neutrons":28,"relative_atomic_mass":42.01778,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-43","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":43,"neutrons":29,"relative_atomic_mass":43.0248,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-44","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":44,"neutrons":30,"relative_atomic_mass":44.03061,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"Si-45","atomic_number":14,"element_symbol":"Si","nist_symbol":"Si","mass_number":45,"neutrons":31,"relative_atomic_mass":45.03995,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[28.084,28.086]","notes":null},{"isotope":"P-24","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":24,"neutrons":9,"relative_atomic_mass":24.03577,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-25","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":25,"neutrons":10,"relative_atomic_mass":25.02119,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-26","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":26,"neutrons":11,"relative_atomic_mass":26.01178,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-27","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":27,"neutrons":12,"relative_atomic_mass":26.999224,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-28","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":28,"neutrons":13,"relative_atomic_mass":27.9923266,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-29","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":29,"neutrons":14,"relative_atomic_mass":28.98180079,"relative_atomic_mass_uncertainty":6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-30","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":30,"neutrons":15,"relative_atomic_mass":29.97831375,"relative_atomic_mass_uncertainty":3.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-31","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":31,"neutrons":16,"relative_atomic_mass":30.97376199842,"relative_atomic_mass_uncertainty":7e-10,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-32","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":32,"neutrons":17,"relative_atomic_mass":31.973907643,"relative_atomic_mass_uncertainty":4.2e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-33","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":33,"neutrons":18,"relative_atomic_mass":32.9717257,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-34","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":34,"neutrons":19,"relative_atomic_mass":33.97364589,"relative_atomic_mass_uncertainty":8.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-35","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":35,"neutrons":20,"relative_atomic_mass":34.9733141,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-36","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":36,"neutrons":21,"relative_atomic_mass":35.97826,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-37","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":37,"neutrons":22,"relative_atomic_mass":36.979607,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-38","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":38,"neutrons":23,"relative_atomic_mass":37.984252,"relative_atomic_mass_uncertainty":0.000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-39","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":39,"neutrons":24,"relative_atomic_mass":38.986227,"relative_atomic_mass_uncertainty":0.000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-40","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":40,"neutrons":25,"relative_atomic_mass":39.99133,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-41","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":41,"neutrons":26,"relative_atomic_mass":40.994654,"relative_atomic_mass_uncertainty":0.000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-42","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":42,"neutrons":27,"relative_atomic_mass":42.00108,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-43","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":43,"neutrons":28,"relative_atomic_mass":43.00502,"relative_atomic_mass_uncertainty":0.0004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-44","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":44,"neutrons":29,"relative_atomic_mass":44.01121,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-45","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":45,"neutrons":30,"relative_atomic_mass":45.01645,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-46","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":46,"neutrons":31,"relative_atomic_mass":46.02446,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"P-47","atomic_number":15,"element_symbol":"P","nist_symbol":"P","mass_number":47,"neutrons":32,"relative_atomic_mass":47.03139,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"30.973761998(5)","notes":null},{"isotope":"S-26","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":26,"neutrons":10,"relative_atomic_mass":26.02907,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-27","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":27,"neutrons":11,"relative_atomic_mass":27.01828,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-28","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":28,"neutrons":12,"relative_atomic_mass":28.00437,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-29","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":29,"neutrons":13,"relative_atomic_mass":28.996611,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-30","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":30,"neutrons":14,"relative_atomic_mass":29.98490703,"relative_atomic_mass_uncertainty":4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-31","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":31,"neutrons":15,"relative_atomic_mass":30.97955701,"relative_atomic_mass_uncertainty":2.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-32","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":32,"neutrons":16,"relative_atomic_mass":31.9720711744,"relative_atomic_mass_uncertainty":1.4e-9,"mass_estimated":false,"natural_abundance":0.9499,"natural_abundance_uncertainty":0.0026,"naturally_occurring":true,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-33","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":33,"neutrons":17,"relative_atomic_mass":32.9714589098,"relative_atomic_mass_uncertainty":1.5e-9,"mass_estimated":false,"natural_abundance":0.0075,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-34","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":34,"neutrons":18,"relative_atomic_mass":33.967867004,"relative_atomic_mass_uncertainty":4.7e-8,"mass_estimated":false,"natural_abundance":0.0425,"natural_abundance_uncertainty":0.0024,"naturally_occurring":true,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-35","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":35,"neutrons":19,"relative_atomic_mass":34.96903231,"relative_atomic_mass_uncertainty":4.3e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-36","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":36,"neutrons":20,"relative_atomic_mass":35.96708071,"relative_atomic_mass_uncertainty":2e-7,"mass_estimated":false,"natural_abundance":0.0001,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-37","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":37,"neutrons":21,"relative_atomic_mass":36.97112551,"relative_atomic_mass_uncertainty":2.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-38","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":38,"neutrons":22,"relative_atomic_mass":37.9711633,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-39","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":39,"neutrons":23,"relative_atomic_mass":38.975134,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-40","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":40,"neutrons":24,"relative_atomic_mass":39.9754826,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-41","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":41,"neutrons":25,"relative_atomic_mass":40.9795935,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-42","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":42,"neutrons":26,"relative_atomic_mass":41.9810651,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-43","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":43,"neutrons":27,"relative_atomic_mass":42.9869076,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-44","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":44,"neutrons":28,"relative_atomic_mass":43.9901188,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-45","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":45,"neutrons":29,"relative_atomic_mass":44.99572,"relative_atomic_mass_uncertainty":0.00074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-46","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":46,"neutrons":30,"relative_atomic_mass":46.00004,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-47","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":47,"neutrons":31,"relative_atomic_mass":47.00795,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-48","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":48,"neutrons":32,"relative_atomic_mass":48.0137,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"S-49","atomic_number":16,"element_symbol":"S","nist_symbol":"S","mass_number":49,"neutrons":33,"relative_atomic_mass":49.02276,"relative_atomic_mass_uncertainty":0.00072,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[32.059,32.076]","notes":null},{"isotope":"Cl-28","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":28,"neutrons":11,"relative_atomic_mass":28.02954,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-29","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":29,"neutrons":12,"relative_atomic_mass":29.01478,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-30","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":30,"neutrons":13,"relative_atomic_mass":30.00477,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-31","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":31,"neutrons":14,"relative_atomic_mass":30.992414,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-32","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":32,"neutrons":15,"relative_atomic_mass":31.98568464,"relative_atomic_mass_uncertainty":6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-33","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":33,"neutrons":16,"relative_atomic_mass":32.97745199,"relative_atomic_mass_uncertainty":4.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-34","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":34,"neutrons":17,"relative_atomic_mass":33.973762485,"relative_atomic_mass_uncertainty":5.2e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-35","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":35,"neutrons":18,"relative_atomic_mass":34.968852682,"relative_atomic_mass_uncertainty":3.7e-8,"mass_estimated":false,"natural_abundance":0.7576,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-36","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":36,"neutrons":19,"relative_atomic_mass":35.968306809,"relative_atomic_mass_uncertainty":3.8e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-37","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":37,"neutrons":20,"relative_atomic_mass":36.965902602,"relative_atomic_mass_uncertainty":5.5e-8,"mass_estimated":false,"natural_abundance":0.2424,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-38","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":38,"neutrons":21,"relative_atomic_mass":37.96801044,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-39","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":39,"neutrons":22,"relative_atomic_mass":38.9680082,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-40","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":40,"neutrons":23,"relative_atomic_mass":39.970415,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-41","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":41,"neutrons":24,"relative_atomic_mass":40.970685,"relative_atomic_mass_uncertainty":0.000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-42","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":42,"neutrons":25,"relative_atomic_mass":41.97325,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-43","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":43,"neutrons":26,"relative_atomic_mass":42.97389,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-44","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":44,"neutrons":27,"relative_atomic_mass":43.97787,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-45","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":45,"neutrons":28,"relative_atomic_mass":44.98029,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-46","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":46,"neutrons":29,"relative_atomic_mass":45.98517,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-47","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":47,"neutrons":30,"relative_atomic_mass":46.98916,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-48","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":48,"neutrons":31,"relative_atomic_mass":47.99564,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-49","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":49,"neutrons":32,"relative_atomic_mass":49.00123,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-50","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":50,"neutrons":33,"relative_atomic_mass":50.00905,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Cl-51","atomic_number":17,"element_symbol":"Cl","nist_symbol":"Cl","mass_number":51,"neutrons":34,"relative_atomic_mass":51.01554,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[35.446,35.457]","notes":"m: modified isotopic compositions in commercial material"},{"isotope":"Ar-30","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":30,"neutrons":12,"relative_atomic_mass":30.02307,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-31","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":31,"neutrons":13,"relative_atomic_mass":31.01212,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-32","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":32,"neutrons":14,"relative_atomic_mass":31.9976378,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-33","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":33,"neutrons":15,"relative_atomic_mass":32.98992555,"relative_atomic_mass_uncertainty":4.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-34","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":34,"neutrons":16,"relative_atomic_mass":33.98027009,"relative_atomic_mass_uncertainty":8.3e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-35","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":35,"neutrons":17,"relative_atomic_mass":34.97525759,"relative_atomic_mass_uncertainty":8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-36","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":36,"neutrons":18,"relative_atomic_mass":35.967545105,"relative_atomic_mass_uncertainty":2.8e-8,"mass_estimated":false,"natural_abundance":0.003336,"natural_abundance_uncertainty":0.000021,"naturally_occurring":true,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-37","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":37,"neutrons":19,"relative_atomic_mass":36.96677633,"relative_atomic_mass_uncertainty":2.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-38","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":38,"neutrons":20,"relative_atomic_mass":37.96273211,"relative_atomic_mass_uncertainty":2.1e-7,"mass_estimated":false,"natural_abundance":0.000629,"natural_abundance_uncertainty":0.000007,"naturally_occurring":true,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-39","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":39,"neutrons":21,"relative_atomic_mass":38.964313,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-40","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":40,"neutrons":22,"relative_atomic_mass":39.9623831237,"relative_atomic_mass_uncertainty":2.4e-9,"mass_estimated":false,"natural_abundance":0.996035,"natural_abundance_uncertainty":0.000025,"naturally_occurring":true,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-41","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":41,"neutrons":23,"relative_atomic_mass":40.96450057,"relative_atomic_mass_uncertainty":3.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-42","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":42,"neutrons":24,"relative_atomic_mass":41.9630457,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-43","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":43,"neutrons":25,"relative_atomic_mass":42.9656361,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-44","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":44,"neutrons":26,"relative_atomic_mass":43.9649238,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-45","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":45,"neutrons":27,"relative_atomic_mass":44.96803973,"relative_atomic_mass_uncertainty":5.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-46","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":46,"neutrons":28,"relative_atomic_mass":45.968083,"relative_atomic_mass_uncertainty":0.000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-47","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":47,"neutrons":29,"relative_atomic_mass":46.972935,"relative_atomic_mass_uncertainty":0.000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-48","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":48,"neutrons":30,"relative_atomic_mass":47.97591,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-49","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":49,"neutrons":31,"relative_atomic_mass":48.9819,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-50","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":50,"neutrons":32,"relative_atomic_mass":49.98613,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-51","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":51,"neutrons":33,"relative_atomic_mass":50.9937,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-52","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":52,"neutrons":34,"relative_atomic_mass":51.99896,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Ar-53","atomic_number":18,"element_symbol":"Ar","nist_symbol":"Ar","mass_number":53,"neutrons":35,"relative_atomic_mass":53.00729,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.948(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"K-32","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":32,"neutrons":13,"relative_atomic_mass":32.02265,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-33","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":33,"neutrons":14,"relative_atomic_mass":33.00756,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-34","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":34,"neutrons":15,"relative_atomic_mass":33.99869,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-35","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":35,"neutrons":16,"relative_atomic_mass":34.98800541,"relative_atomic_mass_uncertainty":5.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-36","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":36,"neutrons":17,"relative_atomic_mass":35.98130201,"relative_atomic_mass_uncertainty":3.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-37","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":37,"neutrons":18,"relative_atomic_mass":36.97337589,"relative_atomic_mass_uncertainty":1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-38","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":38,"neutrons":19,"relative_atomic_mass":37.96908112,"relative_atomic_mass_uncertainty":2.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-39","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":39,"neutrons":20,"relative_atomic_mass":38.9637064864,"relative_atomic_mass_uncertainty":4.9e-9,"mass_estimated":false,"natural_abundance":0.932581,"natural_abundance_uncertainty":0.000044,"naturally_occurring":true,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-40","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":40,"neutrons":21,"relative_atomic_mass":39.963998166,"relative_atomic_mass_uncertainty":6e-8,"mass_estimated":false,"natural_abundance":0.000117,"natural_abundance_uncertainty":0.000001,"naturally_occurring":true,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-41","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":41,"neutrons":22,"relative_atomic_mass":40.9618252579,"relative_atomic_mass_uncertainty":4.1e-9,"mass_estimated":false,"natural_abundance":0.067302,"natural_abundance_uncertainty":0.000044,"naturally_occurring":true,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-42","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":42,"neutrons":23,"relative_atomic_mass":41.96240231,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-43","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":43,"neutrons":24,"relative_atomic_mass":42.9607347,"relative_atomic_mass_uncertainty":4.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-44","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":44,"neutrons":25,"relative_atomic_mass":43.96158699,"relative_atomic_mass_uncertainty":4.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-45","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":45,"neutrons":26,"relative_atomic_mass":44.96069149,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-46","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":46,"neutrons":27,"relative_atomic_mass":45.96198159,"relative_atomic_mass_uncertainty":7.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-47","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":47,"neutrons":28,"relative_atomic_mass":46.9616616,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-48","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":48,"neutrons":29,"relative_atomic_mass":47.96534119,"relative_atomic_mass_uncertainty":8.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-49","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":49,"neutrons":30,"relative_atomic_mass":48.96821075,"relative_atomic_mass_uncertainty":8.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-50","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":50,"neutrons":31,"relative_atomic_mass":49.97238,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-51","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":51,"neutrons":32,"relative_atomic_mass":50.975828,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-52","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":52,"neutrons":33,"relative_atomic_mass":51.98224,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-53","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":53,"neutrons":34,"relative_atomic_mass":52.98746,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-54","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":54,"neutrons":35,"relative_atomic_mass":53.99463,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-55","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":55,"neutrons":36,"relative_atomic_mass":55.00076,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"K-56","atomic_number":19,"element_symbol":"K","nist_symbol":"K","mass_number":56,"neutrons":37,"relative_atomic_mass":56.00851,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"39.0983(1)","notes":null},{"isotope":"Ca-34","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":34,"neutrons":14,"relative_atomic_mass":34.01487,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-35","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":35,"neutrons":15,"relative_atomic_mass":35.00514,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-36","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":36,"neutrons":16,"relative_atomic_mass":35.993074,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-37","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":37,"neutrons":17,"relative_atomic_mass":36.98589785,"relative_atomic_mass_uncertainty":6.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-38","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":38,"neutrons":18,"relative_atomic_mass":37.97631922,"relative_atomic_mass_uncertainty":2.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-39","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":39,"neutrons":19,"relative_atomic_mass":38.97071081,"relative_atomic_mass_uncertainty":6.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-40","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":40,"neutrons":20,"relative_atomic_mass":39.962590863,"relative_atomic_mass_uncertainty":2.2e-8,"mass_estimated":false,"natural_abundance":0.96941,"natural_abundance_uncertainty":0.00156,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-41","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":41,"neutrons":21,"relative_atomic_mass":40.96227792,"relative_atomic_mass_uncertainty":1.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-42","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":42,"neutrons":22,"relative_atomic_mass":41.95861783,"relative_atomic_mass_uncertainty":1.6e-7,"mass_estimated":false,"natural_abundance":0.00647,"natural_abundance_uncertainty":0.00023,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-43","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":43,"neutrons":23,"relative_atomic_mass":42.95876644,"relative_atomic_mass_uncertainty":2.4e-7,"mass_estimated":false,"natural_abundance":0.00135,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-44","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":44,"neutrons":24,"relative_atomic_mass":43.95548156,"relative_atomic_mass_uncertainty":3.5e-7,"mass_estimated":false,"natural_abundance":0.02086,"natural_abundance_uncertainty":0.0011,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-45","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":45,"neutrons":25,"relative_atomic_mass":44.95618635,"relative_atomic_mass_uncertainty":3.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-46","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":46,"neutrons":26,"relative_atomic_mass":45.953689,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":0.00004,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-47","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":47,"neutrons":27,"relative_atomic_mass":46.9545424,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-48","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":48,"neutrons":28,"relative_atomic_mass":47.95252276,"relative_atomic_mass_uncertainty":1.3e-7,"mass_estimated":false,"natural_abundance":0.00187,"natural_abundance_uncertainty":0.00021,"naturally_occurring":true,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-49","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":49,"neutrons":29,"relative_atomic_mass":48.95566274,"relative_atomic_mass_uncertainty":2.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-50","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":50,"neutrons":30,"relative_atomic_mass":49.9574992,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-51","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":51,"neutrons":31,"relative_atomic_mass":50.960989,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-52","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":52,"neutrons":32,"relative_atomic_mass":51.963217,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-53","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":53,"neutrons":33,"relative_atomic_mass":52.96945,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-54","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":54,"neutrons":34,"relative_atomic_mass":53.9734,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-55","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":55,"neutrons":35,"relative_atomic_mass":54.9803,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-56","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":56,"neutrons":36,"relative_atomic_mass":55.98508,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-57","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":57,"neutrons":37,"relative_atomic_mass":56.99262,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ca-58","atomic_number":20,"element_symbol":"Ca","nist_symbol":"Ca","mass_number":58,"neutrons":38,"relative_atomic_mass":57.99794,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"40.078(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sc-36","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":36,"neutrons":15,"relative_atomic_mass":36.01648,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-37","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":37,"neutrons":16,"relative_atomic_mass":37.00374,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-38","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":38,"neutrons":17,"relative_atomic_mass":37.99512,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-39","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":39,"neutrons":18,"relative_atomic_mass":38.984785,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-40","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":40,"neutrons":19,"relative_atomic_mass":39.9779673,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-41","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":41,"neutrons":20,"relative_atomic_mass":40.969251105,"relative_atomic_mass_uncertainty":8.8e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-42","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":42,"neutrons":21,"relative_atomic_mass":41.96551653,"relative_atomic_mass_uncertainty":1.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-43","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":43,"neutrons":22,"relative_atomic_mass":42.9611505,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-44","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":44,"neutrons":23,"relative_atomic_mass":43.9594029,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-45","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":45,"neutrons":24,"relative_atomic_mass":44.95590828,"relative_atomic_mass_uncertainty":7.7e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-46","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":46,"neutrons":25,"relative_atomic_mass":45.95516826,"relative_atomic_mass_uncertainty":7.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-47","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":47,"neutrons":26,"relative_atomic_mass":46.9524037,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-48","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":48,"neutrons":27,"relative_atomic_mass":47.9522236,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-49","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":49,"neutrons":28,"relative_atomic_mass":48.9500146,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-50","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":50,"neutrons":29,"relative_atomic_mass":49.952176,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-51","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":51,"neutrons":30,"relative_atomic_mass":50.953592,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-52","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":52,"neutrons":31,"relative_atomic_mass":51.95688,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-53","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":53,"neutrons":32,"relative_atomic_mass":52.95909,"relative_atomic_mass_uncertainty":0.00029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-54","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":54,"neutrons":33,"relative_atomic_mass":53.96393,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-55","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":55,"neutrons":34,"relative_atomic_mass":54.96782,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-56","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":56,"neutrons":35,"relative_atomic_mass":55.97345,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-57","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":57,"neutrons":36,"relative_atomic_mass":56.97777,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-58","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":58,"neutrons":37,"relative_atomic_mass":57.98403,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-59","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":59,"neutrons":38,"relative_atomic_mass":58.98894,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-60","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":60,"neutrons":39,"relative_atomic_mass":59.99565,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Sc-61","atomic_number":21,"element_symbol":"Sc","nist_symbol":"Sc","mass_number":61,"neutrons":40,"relative_atomic_mass":61.001,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"44.955908(5)","notes":null},{"isotope":"Ti-38","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":38,"neutrons":16,"relative_atomic_mass":38.01145,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-39","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":39,"neutrons":17,"relative_atomic_mass":39.00236,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-40","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":40,"neutrons":18,"relative_atomic_mass":39.9905,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-41","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":41,"neutrons":19,"relative_atomic_mass":40.983148,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-42","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":42,"neutrons":20,"relative_atomic_mass":41.97304903,"relative_atomic_mass_uncertainty":3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-43","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":43,"neutrons":21,"relative_atomic_mass":42.9685225,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-44","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":44,"neutrons":22,"relative_atomic_mass":43.95968995,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-45","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":45,"neutrons":23,"relative_atomic_mass":44.95812198,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-46","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":46,"neutrons":24,"relative_atomic_mass":45.95262772,"relative_atomic_mass_uncertainty":3.5e-7,"mass_estimated":false,"natural_abundance":0.0825,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-47","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":47,"neutrons":25,"relative_atomic_mass":46.95175879,"relative_atomic_mass_uncertainty":3.8e-7,"mass_estimated":false,"natural_abundance":0.0744,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-48","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":48,"neutrons":26,"relative_atomic_mass":47.94794198,"relative_atomic_mass_uncertainty":3.8e-7,"mass_estimated":false,"natural_abundance":0.7372,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-49","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":49,"neutrons":27,"relative_atomic_mass":48.94786568,"relative_atomic_mass_uncertainty":3.9e-7,"mass_estimated":false,"natural_abundance":0.0541,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-50","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":50,"neutrons":28,"relative_atomic_mass":49.94478689,"relative_atomic_mass_uncertainty":3.9e-7,"mass_estimated":false,"natural_abundance":0.0518,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-51","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":51,"neutrons":29,"relative_atomic_mass":50.94661065,"relative_atomic_mass_uncertainty":6.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-52","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":52,"neutrons":30,"relative_atomic_mass":51.946893,"relative_atomic_mass_uncertainty":0.0000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-53","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":53,"neutrons":31,"relative_atomic_mass":52.94973,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-54","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":54,"neutrons":32,"relative_atomic_mass":53.95105,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-55","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":55,"neutrons":33,"relative_atomic_mass":54.95527,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-56","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":56,"neutrons":34,"relative_atomic_mass":55.95791,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-57","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":57,"neutrons":35,"relative_atomic_mass":56.96364,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-58","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":58,"neutrons":36,"relative_atomic_mass":57.9666,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-59","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":59,"neutrons":37,"relative_atomic_mass":58.97247,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-60","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":60,"neutrons":38,"relative_atomic_mass":59.97603,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-61","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":61,"neutrons":39,"relative_atomic_mass":60.98245,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-62","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":62,"neutrons":40,"relative_atomic_mass":61.98651,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"Ti-63","atomic_number":22,"element_symbol":"Ti","nist_symbol":"Ti","mass_number":63,"neutrons":41,"relative_atomic_mass":62.99375,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"47.867(1)","notes":null},{"isotope":"V-40","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":40,"neutrons":17,"relative_atomic_mass":40.01276,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-41","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":41,"neutrons":18,"relative_atomic_mass":41.00021,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-42","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":42,"neutrons":19,"relative_atomic_mass":41.99182,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-43","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":43,"neutrons":20,"relative_atomic_mass":42.980766,"relative_atomic_mass_uncertainty":0.000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-44","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":44,"neutrons":21,"relative_atomic_mass":43.97411,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-45","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":45,"neutrons":22,"relative_atomic_mass":44.9657748,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-46","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":46,"neutrons":23,"relative_atomic_mass":45.96019878,"relative_atomic_mass_uncertainty":3.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-47","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":47,"neutrons":24,"relative_atomic_mass":46.95490491,"relative_atomic_mass_uncertainty":3.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-48","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":48,"neutrons":25,"relative_atomic_mass":47.9522522,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-49","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":49,"neutrons":26,"relative_atomic_mass":48.9485118,"relative_atomic_mass_uncertainty":9.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-50","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":50,"neutrons":27,"relative_atomic_mass":49.94715601,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":0.0025,"natural_abundance_uncertainty":0.00004,"naturally_occurring":true,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-51","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":51,"neutrons":28,"relative_atomic_mass":50.94395704,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":0.9975,"natural_abundance_uncertainty":0.00004,"naturally_occurring":true,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-52","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":52,"neutrons":29,"relative_atomic_mass":51.94477301,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-53","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":53,"neutrons":30,"relative_atomic_mass":52.9443367,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-54","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":54,"neutrons":31,"relative_atomic_mass":53.946439,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-55","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":55,"neutrons":32,"relative_atomic_mass":54.94724,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-56","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":56,"neutrons":33,"relative_atomic_mass":55.95048,"relative_atomic_mass_uncertainty":0.00019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-57","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":57,"neutrons":34,"relative_atomic_mass":56.95252,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-58","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":58,"neutrons":35,"relative_atomic_mass":57.95672,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-59","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":59,"neutrons":36,"relative_atomic_mass":58.95939,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-60","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":60,"neutrons":37,"relative_atomic_mass":59.96431,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-61","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":61,"neutrons":38,"relative_atomic_mass":60.96725,"relative_atomic_mass_uncertainty":0.00096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-62","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":62,"neutrons":39,"relative_atomic_mass":61.97265,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-63","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":63,"neutrons":40,"relative_atomic_mass":62.97639,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-64","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":64,"neutrons":41,"relative_atomic_mass":63.98264,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-65","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":65,"neutrons":42,"relative_atomic_mass":64.9875,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"V-66","atomic_number":23,"element_symbol":"V","nist_symbol":"V","mass_number":66,"neutrons":43,"relative_atomic_mass":65.99398,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"50.9415(1)","notes":null},{"isotope":"Cr-42","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":42,"neutrons":18,"relative_atomic_mass":42.0067,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-43","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":43,"neutrons":19,"relative_atomic_mass":42.99753,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-44","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":44,"neutrons":20,"relative_atomic_mass":43.98536,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-45","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":45,"neutrons":21,"relative_atomic_mass":44.97905,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-46","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":46,"neutrons":22,"relative_atomic_mass":45.968359,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-47","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":47,"neutrons":23,"relative_atomic_mass":46.9628974,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-48","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":48,"neutrons":24,"relative_atomic_mass":47.9540291,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-49","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":49,"neutrons":25,"relative_atomic_mass":48.9513333,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-50","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":50,"neutrons":26,"relative_atomic_mass":49.94604183,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":0.04345,"natural_abundance_uncertainty":0.00013,"naturally_occurring":true,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-51","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":51,"neutrons":27,"relative_atomic_mass":50.94476502,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-52","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":52,"neutrons":28,"relative_atomic_mass":51.94050623,"relative_atomic_mass_uncertainty":6.3e-7,"mass_estimated":false,"natural_abundance":0.83789,"natural_abundance_uncertainty":0.00018,"naturally_occurring":true,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-53","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":53,"neutrons":29,"relative_atomic_mass":52.94064815,"relative_atomic_mass_uncertainty":6.2e-7,"mass_estimated":false,"natural_abundance":0.09501,"natural_abundance_uncertainty":0.00017,"naturally_occurring":true,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-54","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":54,"neutrons":30,"relative_atomic_mass":53.93887916,"relative_atomic_mass_uncertainty":6.1e-7,"mass_estimated":false,"natural_abundance":0.02365,"natural_abundance_uncertainty":0.00007,"naturally_occurring":true,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-55","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":55,"neutrons":31,"relative_atomic_mass":54.94083843,"relative_atomic_mass_uncertainty":6.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-56","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":56,"neutrons":32,"relative_atomic_mass":55.9406531,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-57","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":57,"neutrons":33,"relative_atomic_mass":56.943613,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-58","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":58,"neutrons":34,"relative_atomic_mass":57.94435,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-59","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":59,"neutrons":35,"relative_atomic_mass":58.94859,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-60","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":60,"neutrons":36,"relative_atomic_mass":59.95008,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-61","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":61,"neutrons":37,"relative_atomic_mass":60.95442,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-62","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":62,"neutrons":38,"relative_atomic_mass":61.9561,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-63","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":63,"neutrons":39,"relative_atomic_mass":62.96165,"relative_atomic_mass_uncertainty":0.00049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-64","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":64,"neutrons":40,"relative_atomic_mass":63.96408,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-65","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":65,"neutrons":41,"relative_atomic_mass":64.96996,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-66","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":66,"neutrons":42,"relative_atomic_mass":65.97366,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-67","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":67,"neutrons":43,"relative_atomic_mass":66.98016,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Cr-68","atomic_number":24,"element_symbol":"Cr","nist_symbol":"Cr","mass_number":68,"neutrons":44,"relative_atomic_mass":67.98403,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"51.9961(6)","notes":null},{"isotope":"Mn-44","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":44,"neutrons":19,"relative_atomic_mass":44.00715,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-45","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":45,"neutrons":20,"relative_atomic_mass":44.99449,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-46","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":46,"neutrons":21,"relative_atomic_mass":45.98609,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-47","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":47,"neutrons":22,"relative_atomic_mass":46.975775,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-48","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":48,"neutrons":23,"relative_atomic_mass":47.96852,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-49","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":49,"neutrons":24,"relative_atomic_mass":48.959595,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-50","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":50,"neutrons":25,"relative_atomic_mass":49.95423778,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-51","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":51,"neutrons":26,"relative_atomic_mass":50.94820847,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-52","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":52,"neutrons":27,"relative_atomic_mass":51.9455639,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-53","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":53,"neutrons":28,"relative_atomic_mass":52.94128889,"relative_atomic_mass_uncertainty":6.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-54","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":54,"neutrons":29,"relative_atomic_mass":53.9403576,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-55","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":55,"neutrons":30,"relative_atomic_mass":54.93804391,"relative_atomic_mass_uncertainty":4.8e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-56","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":56,"neutrons":31,"relative_atomic_mass":55.93890369,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-57","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":57,"neutrons":32,"relative_atomic_mass":56.9382861,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-58","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":58,"neutrons":33,"relative_atomic_mass":57.9400666,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-59","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":59,"neutrons":34,"relative_atomic_mass":58.9403911,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-60","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":60,"neutrons":35,"relative_atomic_mass":59.9431366,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-61","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":61,"neutrons":36,"relative_atomic_mass":60.9444525,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-62","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":62,"neutrons":37,"relative_atomic_mass":61.94795,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-63","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":63,"neutrons":38,"relative_atomic_mass":62.9496647,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-64","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":64,"neutrons":39,"relative_atomic_mass":63.9538494,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-65","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":65,"neutrons":40,"relative_atomic_mass":64.9560198,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-66","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":66,"neutrons":41,"relative_atomic_mass":65.960547,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-67","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":67,"neutrons":42,"relative_atomic_mass":66.96424,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-68","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":68,"neutrons":43,"relative_atomic_mass":67.96962,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-69","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":69,"neutrons":44,"relative_atomic_mass":68.97366,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-70","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":70,"neutrons":45,"relative_atomic_mass":69.97937,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Mn-71","atomic_number":25,"element_symbol":"Mn","nist_symbol":"Mn","mass_number":71,"neutrons":46,"relative_atomic_mass":70.98368,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"54.938044(3)","notes":null},{"isotope":"Fe-45","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":45,"neutrons":19,"relative_atomic_mass":45.01442,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-46","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":46,"neutrons":20,"relative_atomic_mass":46.00063,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-47","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":47,"neutrons":21,"relative_atomic_mass":46.99185,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-48","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":48,"neutrons":22,"relative_atomic_mass":47.98023,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-49","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":49,"neutrons":23,"relative_atomic_mass":48.973429,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-50","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":50,"neutrons":24,"relative_atomic_mass":49.962975,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-51","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":51,"neutrons":25,"relative_atomic_mass":50.956841,"relative_atomic_mass_uncertainty":0.0000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-52","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":52,"neutrons":26,"relative_atomic_mass":51.9481131,"relative_atomic_mass_uncertainty":0.000007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-53","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":53,"neutrons":27,"relative_atomic_mass":52.9453064,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-54","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":54,"neutrons":28,"relative_atomic_mass":53.93960899,"relative_atomic_mass_uncertainty":5.3e-7,"mass_estimated":false,"natural_abundance":0.05845,"natural_abundance_uncertainty":0.00035,"naturally_occurring":true,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-55","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":55,"neutrons":29,"relative_atomic_mass":54.93829199,"relative_atomic_mass_uncertainty":5.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-56","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":56,"neutrons":30,"relative_atomic_mass":55.93493633,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":0.91754,"natural_abundance_uncertainty":0.00036,"naturally_occurring":true,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-57","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":57,"neutrons":31,"relative_atomic_mass":56.93539284,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":0.02119,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-58","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":58,"neutrons":32,"relative_atomic_mass":57.93327443,"relative_atomic_mass_uncertainty":5.3e-7,"mass_estimated":false,"natural_abundance":0.00282,"natural_abundance_uncertainty":0.00004,"naturally_occurring":true,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-59","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":59,"neutrons":33,"relative_atomic_mass":58.93487434,"relative_atomic_mass_uncertainty":5.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-60","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":60,"neutrons":34,"relative_atomic_mass":59.9340711,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-61","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":61,"neutrons":35,"relative_atomic_mass":60.9367462,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-62","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":62,"neutrons":36,"relative_atomic_mass":61.9367918,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-63","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":63,"neutrons":37,"relative_atomic_mass":62.9402727,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-64","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":64,"neutrons":38,"relative_atomic_mass":63.9409878,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-65","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":65,"neutrons":39,"relative_atomic_mass":64.9450115,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-66","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":66,"neutrons":40,"relative_atomic_mass":65.94625,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-67","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":67,"neutrons":41,"relative_atomic_mass":66.95054,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-68","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":68,"neutrons":42,"relative_atomic_mass":67.95295,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-69","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":69,"neutrons":43,"relative_atomic_mass":68.95807,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-70","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":70,"neutrons":44,"relative_atomic_mass":69.96102,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-71","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":71,"neutrons":45,"relative_atomic_mass":70.96672,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-72","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":72,"neutrons":46,"relative_atomic_mass":71.96983,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-73","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":73,"neutrons":47,"relative_atomic_mass":72.97572,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Fe-74","atomic_number":26,"element_symbol":"Fe","nist_symbol":"Fe","mass_number":74,"neutrons":48,"relative_atomic_mass":73.97935,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"55.845(2)","notes":null},{"isotope":"Co-47","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":47,"neutrons":20,"relative_atomic_mass":47.01057,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-48","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":48,"neutrons":21,"relative_atomic_mass":48.00093,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-49","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":49,"neutrons":22,"relative_atomic_mass":48.98891,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-50","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":50,"neutrons":23,"relative_atomic_mass":49.98091,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-51","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":51,"neutrons":24,"relative_atomic_mass":50.970647,"relative_atomic_mass_uncertainty":0.000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-52","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":52,"neutrons":25,"relative_atomic_mass":51.96351,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-53","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":53,"neutrons":26,"relative_atomic_mass":52.9542041,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-54","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":54,"neutrons":27,"relative_atomic_mass":53.94845987,"relative_atomic_mass_uncertainty":5.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-55","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":55,"neutrons":28,"relative_atomic_mass":54.9419972,"relative_atomic_mass_uncertainty":5.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-56","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":56,"neutrons":29,"relative_atomic_mass":55.9398388,"relative_atomic_mass_uncertainty":6.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-57","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":57,"neutrons":30,"relative_atomic_mass":56.93629057,"relative_atomic_mass_uncertainty":6.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-58","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":58,"neutrons":31,"relative_atomic_mass":57.9357521,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-59","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":59,"neutrons":32,"relative_atomic_mass":58.93319429,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-60","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":60,"neutrons":33,"relative_atomic_mass":59.9338163,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-61","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":61,"neutrons":34,"relative_atomic_mass":60.93247662,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-62","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":62,"neutrons":35,"relative_atomic_mass":61.934059,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-63","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":63,"neutrons":36,"relative_atomic_mass":62.9336,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-64","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":64,"neutrons":37,"relative_atomic_mass":63.935811,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-65","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":65,"neutrons":38,"relative_atomic_mass":64.9364621,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-66","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":66,"neutrons":39,"relative_atomic_mass":65.939443,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-67","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":67,"neutrons":40,"relative_atomic_mass":66.9406096,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-68","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":68,"neutrons":41,"relative_atomic_mass":67.94426,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-69","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":69,"neutrons":42,"relative_atomic_mass":68.94614,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-70","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":70,"neutrons":43,"relative_atomic_mass":69.94963,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-71","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":71,"neutrons":44,"relative_atomic_mass":70.95237,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-72","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":72,"neutrons":45,"relative_atomic_mass":71.95729,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-73","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":73,"neutrons":46,"relative_atomic_mass":72.96039,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-74","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":74,"neutrons":47,"relative_atomic_mass":73.96515,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-75","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":75,"neutrons":48,"relative_atomic_mass":74.96876,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Co-76","atomic_number":27,"element_symbol":"Co","nist_symbol":"Co","mass_number":76,"neutrons":49,"relative_atomic_mass":75.97413,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.933194(4)","notes":null},{"isotope":"Ni-48","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":48,"neutrons":20,"relative_atomic_mass":48.01769,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-49","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":49,"neutrons":21,"relative_atomic_mass":49.0077,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-50","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":50,"neutrons":22,"relative_atomic_mass":49.99474,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-51","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":51,"neutrons":23,"relative_atomic_mass":50.98611,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-52","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":52,"neutrons":24,"relative_atomic_mass":51.9748,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-53","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":53,"neutrons":25,"relative_atomic_mass":52.96819,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-54","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":54,"neutrons":26,"relative_atomic_mass":53.957892,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-55","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":55,"neutrons":27,"relative_atomic_mass":54.95133063,"relative_atomic_mass_uncertainty":8.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-56","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":56,"neutrons":28,"relative_atomic_mass":55.94212855,"relative_atomic_mass_uncertainty":5.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-57","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":57,"neutrons":29,"relative_atomic_mass":56.93979218,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-58","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":58,"neutrons":30,"relative_atomic_mass":57.93534241,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":0.68077,"natural_abundance_uncertainty":0.00019,"naturally_occurring":true,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-59","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":59,"neutrons":31,"relative_atomic_mass":58.9343462,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-60","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":60,"neutrons":32,"relative_atomic_mass":59.93078588,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":0.26223,"natural_abundance_uncertainty":0.00015,"naturally_occurring":true,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-61","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":61,"neutrons":33,"relative_atomic_mass":60.93105557,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":0.011399,"natural_abundance_uncertainty":0.000013,"naturally_occurring":true,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-62","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":62,"neutrons":34,"relative_atomic_mass":61.92834537,"relative_atomic_mass_uncertainty":5.5e-7,"mass_estimated":false,"natural_abundance":0.036346,"natural_abundance_uncertainty":0.00004,"naturally_occurring":true,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-63","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":63,"neutrons":35,"relative_atomic_mass":62.92966963,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-64","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":64,"neutrons":36,"relative_atomic_mass":63.92796682,"relative_atomic_mass_uncertainty":5.8e-7,"mass_estimated":false,"natural_abundance":0.009255,"natural_abundance_uncertainty":0.000019,"naturally_occurring":true,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-65","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":65,"neutrons":37,"relative_atomic_mass":64.93008517,"relative_atomic_mass_uncertainty":6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-66","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":66,"neutrons":38,"relative_atomic_mass":65.9291393,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-67","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":67,"neutrons":39,"relative_atomic_mass":66.9315694,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-68","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":68,"neutrons":40,"relative_atomic_mass":67.9318688,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-69","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":69,"neutrons":41,"relative_atomic_mass":68.9356103,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-70","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":70,"neutrons":42,"relative_atomic_mass":69.9364313,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-71","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":71,"neutrons":43,"relative_atomic_mass":70.940519,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-72","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":72,"neutrons":44,"relative_atomic_mass":71.9417859,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-73","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":73,"neutrons":45,"relative_atomic_mass":72.9462067,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-74","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":74,"neutrons":46,"relative_atomic_mass":73.94798,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-75","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":75,"neutrons":47,"relative_atomic_mass":74.9525,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-76","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":76,"neutrons":48,"relative_atomic_mass":75.95533,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-77","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":77,"neutrons":49,"relative_atomic_mass":76.96055,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-78","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":78,"neutrons":50,"relative_atomic_mass":77.96336,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ni-79","atomic_number":28,"element_symbol":"Ni","nist_symbol":"Ni","mass_number":79,"neutrons":51,"relative_atomic_mass":78.97025,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"58.6934(4)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-52","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":52,"neutrons":23,"relative_atomic_mass":51.99671,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-53","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":53,"neutrons":24,"relative_atomic_mass":52.98459,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-54","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":54,"neutrons":25,"relative_atomic_mass":53.97666,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-55","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":55,"neutrons":26,"relative_atomic_mass":54.96604,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-56","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":56,"neutrons":27,"relative_atomic_mass":55.95895,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-57","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":57,"neutrons":28,"relative_atomic_mass":56.9492125,"relative_atomic_mass_uncertainty":6.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-58","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":58,"neutrons":29,"relative_atomic_mass":57.94453305,"relative_atomic_mass_uncertainty":7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-59","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":59,"neutrons":30,"relative_atomic_mass":58.93949748,"relative_atomic_mass_uncertainty":6.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-60","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":60,"neutrons":31,"relative_atomic_mass":59.9373645,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-61","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":61,"neutrons":32,"relative_atomic_mass":60.9334576,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-62","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":62,"neutrons":33,"relative_atomic_mass":61.93259541,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-63","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":63,"neutrons":34,"relative_atomic_mass":62.92959772,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":0.6915,"natural_abundance_uncertainty":0.0015,"naturally_occurring":true,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-64","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":64,"neutrons":35,"relative_atomic_mass":63.92976434,"relative_atomic_mass_uncertainty":5.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-65","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":65,"neutrons":36,"relative_atomic_mass":64.9277897,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":0.3085,"natural_abundance_uncertainty":0.0015,"naturally_occurring":true,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-66","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":66,"neutrons":37,"relative_atomic_mass":65.92886903,"relative_atomic_mass_uncertainty":7.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-67","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":67,"neutrons":38,"relative_atomic_mass":66.9277303,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-68","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":68,"neutrons":39,"relative_atomic_mass":67.9296109,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-69","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":69,"neutrons":40,"relative_atomic_mass":68.9294293,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-70","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":70,"neutrons":41,"relative_atomic_mass":69.9323921,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-71","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":71,"neutrons":42,"relative_atomic_mass":70.9326768,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-72","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":72,"neutrons":43,"relative_atomic_mass":71.9358203,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-73","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":73,"neutrons":44,"relative_atomic_mass":72.9366744,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-74","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":74,"neutrons":45,"relative_atomic_mass":73.9398749,"relative_atomic_mass_uncertainty":0.0000066,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-75","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":75,"neutrons":46,"relative_atomic_mass":74.9415226,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-76","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":76,"neutrons":47,"relative_atomic_mass":75.945275,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-77","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":77,"neutrons":48,"relative_atomic_mass":76.94792,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-78","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":78,"neutrons":49,"relative_atomic_mass":77.95223,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-79","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":79,"neutrons":50,"relative_atomic_mass":78.95502,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-80","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":80,"neutrons":51,"relative_atomic_mass":79.96089,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-81","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":81,"neutrons":52,"relative_atomic_mass":80.96587,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Cu-82","atomic_number":29,"element_symbol":"Cu","nist_symbol":"Cu","mass_number":82,"neutrons":53,"relative_atomic_mass":81.97244,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"63.546(3)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-54","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":54,"neutrons":24,"relative_atomic_mass":53.99204,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-55","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":55,"neutrons":25,"relative_atomic_mass":54.98398,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-56","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":56,"neutrons":26,"relative_atomic_mass":55.97254,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-57","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":57,"neutrons":27,"relative_atomic_mass":56.96506,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-58","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":58,"neutrons":28,"relative_atomic_mass":57.954591,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-59","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":59,"neutrons":29,"relative_atomic_mass":58.94931266,"relative_atomic_mass_uncertainty":8.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-60","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":60,"neutrons":30,"relative_atomic_mass":59.9418421,"relative_atomic_mass_uncertainty":6.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-61","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":61,"neutrons":31,"relative_atomic_mass":60.939507,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-62","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":62,"neutrons":32,"relative_atomic_mass":61.93433397,"relative_atomic_mass_uncertainty":7.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-63","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":63,"neutrons":33,"relative_atomic_mass":62.9332115,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-64","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":64,"neutrons":34,"relative_atomic_mass":63.92914201,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":0.4917,"natural_abundance_uncertainty":0.0075,"naturally_occurring":true,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-65","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":65,"neutrons":35,"relative_atomic_mass":64.92924077,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-66","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":66,"neutrons":36,"relative_atomic_mass":65.92603381,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":0.2773,"natural_abundance_uncertainty":0.0098,"naturally_occurring":true,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-67","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":67,"neutrons":37,"relative_atomic_mass":66.92712775,"relative_atomic_mass_uncertainty":9.6e-7,"mass_estimated":false,"natural_abundance":0.0404,"natural_abundance_uncertainty":0.0016,"naturally_occurring":true,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-68","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":68,"neutrons":38,"relative_atomic_mass":67.92484455,"relative_atomic_mass_uncertainty":9.8e-7,"mass_estimated":false,"natural_abundance":0.1845,"natural_abundance_uncertainty":0.0063,"naturally_occurring":true,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-69","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":69,"neutrons":39,"relative_atomic_mass":68.9265507,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-70","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":70,"neutrons":40,"relative_atomic_mass":69.9253192,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":0.0061,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-71","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":71,"neutrons":41,"relative_atomic_mass":70.9277196,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-72","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":72,"neutrons":42,"relative_atomic_mass":71.9268428,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-73","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":73,"neutrons":43,"relative_atomic_mass":72.9295826,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-74","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":74,"neutrons":44,"relative_atomic_mass":73.9294073,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-75","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":75,"neutrons":45,"relative_atomic_mass":74.9328402,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-76","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":76,"neutrons":46,"relative_atomic_mass":75.933115,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-77","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":77,"neutrons":47,"relative_atomic_mass":76.9368872,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-78","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":78,"neutrons":48,"relative_atomic_mass":77.9382892,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-79","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":79,"neutrons":49,"relative_atomic_mass":78.9426381,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-80","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":80,"neutrons":50,"relative_atomic_mass":79.9445529,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-81","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":81,"neutrons":51,"relative_atomic_mass":80.9504026,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-82","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":82,"neutrons":52,"relative_atomic_mass":81.95426,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-83","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":83,"neutrons":53,"relative_atomic_mass":82.96056,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-84","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":84,"neutrons":54,"relative_atomic_mass":83.96521,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Zn-85","atomic_number":30,"element_symbol":"Zn","nist_symbol":"Zn","mass_number":85,"neutrons":55,"relative_atomic_mass":84.97226,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"65.38(2)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Ga-56","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":56,"neutrons":25,"relative_atomic_mass":55.99536,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-57","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":57,"neutrons":26,"relative_atomic_mass":56.9832,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-58","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":58,"neutrons":27,"relative_atomic_mass":57.97478,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-59","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":59,"neutrons":28,"relative_atomic_mass":58.96353,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-60","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":60,"neutrons":29,"relative_atomic_mass":59.95729,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-61","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":61,"neutrons":30,"relative_atomic_mass":60.949399,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-62","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":62,"neutrons":31,"relative_atomic_mass":61.94419025,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-63","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":63,"neutrons":32,"relative_atomic_mass":62.9392942,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-64","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":64,"neutrons":33,"relative_atomic_mass":63.9368404,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-65","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":65,"neutrons":34,"relative_atomic_mass":64.93273459,"relative_atomic_mass_uncertainty":8.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-66","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":66,"neutrons":35,"relative_atomic_mass":65.9315894,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-67","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":67,"neutrons":36,"relative_atomic_mass":66.9282025,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-68","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":68,"neutrons":37,"relative_atomic_mass":67.9279805,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-69","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":69,"neutrons":38,"relative_atomic_mass":68.9255735,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.60108,"natural_abundance_uncertainty":0.00009,"naturally_occurring":true,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-70","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":70,"neutrons":39,"relative_atomic_mass":69.9260219,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-71","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":71,"neutrons":40,"relative_atomic_mass":70.92470258,"relative_atomic_mass_uncertainty":8.7e-7,"mass_estimated":false,"natural_abundance":0.39892,"natural_abundance_uncertainty":0.00009,"naturally_occurring":true,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-72","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":72,"neutrons":41,"relative_atomic_mass":71.92636747,"relative_atomic_mass_uncertainty":8.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-73","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":73,"neutrons":42,"relative_atomic_mass":72.9251747,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-74","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":74,"neutrons":43,"relative_atomic_mass":73.9269457,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-75","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":75,"neutrons":44,"relative_atomic_mass":74.9265002,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-76","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":76,"neutrons":45,"relative_atomic_mass":75.9288276,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-77","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":77,"neutrons":46,"relative_atomic_mass":76.9291543,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-78","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":78,"neutrons":47,"relative_atomic_mass":77.9316088,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-79","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":79,"neutrons":48,"relative_atomic_mass":78.9328523,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-80","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":80,"neutrons":49,"relative_atomic_mass":79.9364208,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-81","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":81,"neutrons":50,"relative_atomic_mass":80.9381338,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-82","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":82,"neutrons":51,"relative_atomic_mass":81.9431765,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-83","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":83,"neutrons":52,"relative_atomic_mass":82.9471203,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-84","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":84,"neutrons":53,"relative_atomic_mass":83.95246,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-85","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":85,"neutrons":54,"relative_atomic_mass":84.95699,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-86","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":86,"neutrons":55,"relative_atomic_mass":85.96301,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ga-87","atomic_number":31,"element_symbol":"Ga","nist_symbol":"Ga","mass_number":87,"neutrons":56,"relative_atomic_mass":86.96824,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"69.723(1)","notes":null},{"isotope":"Ge-58","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":58,"neutrons":26,"relative_atomic_mass":57.99172,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-59","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":59,"neutrons":27,"relative_atomic_mass":58.98249,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-60","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":60,"neutrons":28,"relative_atomic_mass":59.97036,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-61","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":61,"neutrons":29,"relative_atomic_mass":60.96379,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-62","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":62,"neutrons":30,"relative_atomic_mass":61.95502,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-63","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":63,"neutrons":31,"relative_atomic_mass":62.949628,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-64","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":64,"neutrons":32,"relative_atomic_mass":63.9416899,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-65","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":65,"neutrons":33,"relative_atomic_mass":64.9393681,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-66","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":66,"neutrons":34,"relative_atomic_mass":65.9338621,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-67","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":67,"neutrons":35,"relative_atomic_mass":66.9327339,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-68","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":68,"neutrons":36,"relative_atomic_mass":67.9280953,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-69","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":69,"neutrons":37,"relative_atomic_mass":68.9279645,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-70","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":70,"neutrons":38,"relative_atomic_mass":69.92424875,"relative_atomic_mass_uncertainty":9e-7,"mass_estimated":false,"natural_abundance":0.2057,"natural_abundance_uncertainty":0.0027,"naturally_occurring":true,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-71","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":71,"neutrons":39,"relative_atomic_mass":70.92495233,"relative_atomic_mass_uncertainty":9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-72","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":72,"neutrons":40,"relative_atomic_mass":71.922075826,"relative_atomic_mass_uncertainty":8.1e-8,"mass_estimated":false,"natural_abundance":0.2745,"natural_abundance_uncertainty":0.0032,"naturally_occurring":true,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-73","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":73,"neutrons":41,"relative_atomic_mass":72.923458956,"relative_atomic_mass_uncertainty":6.1e-8,"mass_estimated":false,"natural_abundance":0.0775,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-74","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":74,"neutrons":42,"relative_atomic_mass":73.921177761,"relative_atomic_mass_uncertainty":1.3e-8,"mass_estimated":false,"natural_abundance":0.365,"natural_abundance_uncertainty":0.002,"naturally_occurring":true,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-75","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":75,"neutrons":43,"relative_atomic_mass":74.92285837,"relative_atomic_mass_uncertainty":5.5e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-76","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":76,"neutrons":44,"relative_atomic_mass":75.921402726,"relative_atomic_mass_uncertainty":1.9e-8,"mass_estimated":false,"natural_abundance":0.0773,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-77","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":77,"neutrons":45,"relative_atomic_mass":76.923549843,"relative_atomic_mass_uncertainty":5.7e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-78","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":78,"neutrons":46,"relative_atomic_mass":77.9228529,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-79","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":79,"neutrons":47,"relative_atomic_mass":78.92536,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-80","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":80,"neutrons":48,"relative_atomic_mass":79.9253508,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-81","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":81,"neutrons":49,"relative_atomic_mass":80.9288329,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-82","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":82,"neutrons":50,"relative_atomic_mass":81.929774,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-83","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":83,"neutrons":51,"relative_atomic_mass":82.9345391,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-84","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":84,"neutrons":52,"relative_atomic_mass":83.9375751,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-85","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":85,"neutrons":53,"relative_atomic_mass":84.9429697,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-86","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":86,"neutrons":54,"relative_atomic_mass":85.94658,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-87","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":87,"neutrons":55,"relative_atomic_mass":86.95268,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-88","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":88,"neutrons":56,"relative_atomic_mass":87.95691,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-89","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":89,"neutrons":57,"relative_atomic_mass":88.96379,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"Ge-90","atomic_number":32,"element_symbol":"Ge","nist_symbol":"Ge","mass_number":90,"neutrons":58,"relative_atomic_mass":89.96863,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"72.630(8)","notes":null},{"isotope":"As-60","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":60,"neutrons":27,"relative_atomic_mass":59.99388,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-61","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":61,"neutrons":28,"relative_atomic_mass":60.98112,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-62","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":62,"neutrons":29,"relative_atomic_mass":61.97361,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-63","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":63,"neutrons":30,"relative_atomic_mass":62.9639,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-64","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":64,"neutrons":31,"relative_atomic_mass":63.95743,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-65","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":65,"neutrons":32,"relative_atomic_mass":64.949611,"relative_atomic_mass_uncertainty":0.000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-66","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":66,"neutrons":33,"relative_atomic_mass":65.9441488,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-67","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":67,"neutrons":34,"relative_atomic_mass":66.93925111,"relative_atomic_mass_uncertainty":4.8e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-68","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":68,"neutrons":35,"relative_atomic_mass":67.9367741,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-69","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":69,"neutrons":36,"relative_atomic_mass":68.932246,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-70","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":70,"neutrons":37,"relative_atomic_mass":69.930926,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-71","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":71,"neutrons":38,"relative_atomic_mass":70.9271138,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-72","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":72,"neutrons":39,"relative_atomic_mass":71.9267523,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-73","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":73,"neutrons":40,"relative_atomic_mass":72.9238291,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-74","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":74,"neutrons":41,"relative_atomic_mass":73.9239286,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-75","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":75,"neutrons":42,"relative_atomic_mass":74.92159457,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-76","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":76,"neutrons":43,"relative_atomic_mass":75.92239202,"relative_atomic_mass_uncertainty":9.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-77","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":77,"neutrons":44,"relative_atomic_mass":76.9206476,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-78","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":78,"neutrons":45,"relative_atomic_mass":77.921828,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-79","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":79,"neutrons":46,"relative_atomic_mass":78.9209484,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-80","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":80,"neutrons":47,"relative_atomic_mass":79.9224746,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-81","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":81,"neutrons":48,"relative_atomic_mass":80.9221323,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-82","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":82,"neutrons":49,"relative_atomic_mass":81.9247412,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-83","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":83,"neutrons":50,"relative_atomic_mass":82.9252069,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-84","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":84,"neutrons":51,"relative_atomic_mass":83.9293033,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-85","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":85,"neutrons":52,"relative_atomic_mass":84.9321637,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-86","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":86,"neutrons":53,"relative_atomic_mass":85.9367015,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-87","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":87,"neutrons":54,"relative_atomic_mass":86.9402917,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-88","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":88,"neutrons":55,"relative_atomic_mass":87.94555,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-89","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":89,"neutrons":56,"relative_atomic_mass":88.94976,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-90","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":90,"neutrons":57,"relative_atomic_mass":89.95563,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-91","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":91,"neutrons":58,"relative_atomic_mass":90.96039,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"As-92","atomic_number":33,"element_symbol":"As","nist_symbol":"As","mass_number":92,"neutrons":59,"relative_atomic_mass":91.96674,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"74.921595(6)","notes":null},{"isotope":"Se-64","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":64,"neutrons":30,"relative_atomic_mass":63.97109,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-65","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":65,"neutrons":31,"relative_atomic_mass":64.9644,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-66","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":66,"neutrons":32,"relative_atomic_mass":65.95559,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-67","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":67,"neutrons":33,"relative_atomic_mass":66.949994,"relative_atomic_mass_uncertainty":0.000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-68","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":68,"neutrons":34,"relative_atomic_mass":67.94182524,"relative_atomic_mass_uncertainty":5.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-69","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":69,"neutrons":35,"relative_atomic_mass":68.9394148,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-70","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":70,"neutrons":36,"relative_atomic_mass":69.9335155,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-71","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":71,"neutrons":37,"relative_atomic_mass":70.9322094,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-72","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":72,"neutrons":38,"relative_atomic_mass":71.9271405,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-73","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":73,"neutrons":39,"relative_atomic_mass":72.9267549,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-74","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":74,"neutrons":40,"relative_atomic_mass":73.922475934,"relative_atomic_mass_uncertainty":1.5e-8,"mass_estimated":false,"natural_abundance":0.0089,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-75","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":75,"neutrons":41,"relative_atomic_mass":74.92252287,"relative_atomic_mass_uncertainty":7.8e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-76","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":76,"neutrons":42,"relative_atomic_mass":75.919213704,"relative_atomic_mass_uncertainty":1.7e-8,"mass_estimated":false,"natural_abundance":0.0937,"natural_abundance_uncertainty":0.0029,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-77","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":77,"neutrons":43,"relative_atomic_mass":76.919914154,"relative_atomic_mass_uncertainty":6.7e-8,"mass_estimated":false,"natural_abundance":0.0763,"natural_abundance_uncertainty":0.0016,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-78","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":78,"neutrons":44,"relative_atomic_mass":77.91730928,"relative_atomic_mass_uncertainty":2e-7,"mass_estimated":false,"natural_abundance":0.2377,"natural_abundance_uncertainty":0.0028,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-79","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":79,"neutrons":45,"relative_atomic_mass":78.91849929,"relative_atomic_mass_uncertainty":2.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-80","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":80,"neutrons":46,"relative_atomic_mass":79.9165218,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.4961,"natural_abundance_uncertainty":0.0041,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-81","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":81,"neutrons":47,"relative_atomic_mass":80.917993,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-82","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":82,"neutrons":48,"relative_atomic_mass":81.9166995,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":0.0873,"natural_abundance_uncertainty":0.0022,"naturally_occurring":true,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-83","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":83,"neutrons":49,"relative_atomic_mass":82.9191186,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-84","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":84,"neutrons":50,"relative_atomic_mass":83.9184668,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-85","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":85,"neutrons":51,"relative_atomic_mass":84.9222608,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-86","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":86,"neutrons":52,"relative_atomic_mass":85.9243117,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-87","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":87,"neutrons":53,"relative_atomic_mass":86.9286886,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-88","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":88,"neutrons":54,"relative_atomic_mass":87.9314175,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-89","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":89,"neutrons":55,"relative_atomic_mass":88.9366691,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-90","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":90,"neutrons":56,"relative_atomic_mass":89.9401,"relative_atomic_mass_uncertainty":0.00035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-91","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":91,"neutrons":57,"relative_atomic_mass":90.94596,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-92","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":92,"neutrons":58,"relative_atomic_mass":91.94984,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-93","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":93,"neutrons":59,"relative_atomic_mass":92.95629,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-94","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":94,"neutrons":60,"relative_atomic_mass":93.96049,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Se-95","atomic_number":34,"element_symbol":"Se","nist_symbol":"Se","mass_number":95,"neutrons":61,"relative_atomic_mass":94.9673,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"78.971(8)","notes":"r: range in isotopic composition limits precision"},{"isotope":"Br-67","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":67,"neutrons":32,"relative_atomic_mass":66.96465,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-68","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":68,"neutrons":33,"relative_atomic_mass":67.95873,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-69","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":69,"neutrons":34,"relative_atomic_mass":68.950497,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-70","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":70,"neutrons":35,"relative_atomic_mass":69.944792,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-71","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":71,"neutrons":36,"relative_atomic_mass":70.9393422,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-72","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":72,"neutrons":37,"relative_atomic_mass":71.9365886,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-73","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":73,"neutrons":38,"relative_atomic_mass":72.9316715,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-74","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":74,"neutrons":39,"relative_atomic_mass":73.9299102,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-75","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":75,"neutrons":40,"relative_atomic_mass":74.9258105,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-76","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":76,"neutrons":41,"relative_atomic_mass":75.924542,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-77","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":77,"neutrons":42,"relative_atomic_mass":76.9213792,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-78","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":78,"neutrons":43,"relative_atomic_mass":77.9211459,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-79","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":79,"neutrons":44,"relative_atomic_mass":78.9183376,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.5069,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-80","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":80,"neutrons":45,"relative_atomic_mass":79.9185298,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-81","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":81,"neutrons":46,"relative_atomic_mass":80.9162897,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.4931,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-82","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":82,"neutrons":47,"relative_atomic_mass":81.9168032,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-83","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":83,"neutrons":48,"relative_atomic_mass":82.9151756,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-84","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":84,"neutrons":49,"relative_atomic_mass":83.916496,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-85","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":85,"neutrons":50,"relative_atomic_mass":84.9156458,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-86","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":86,"neutrons":51,"relative_atomic_mass":85.9188054,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-87","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":87,"neutrons":52,"relative_atomic_mass":86.920674,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-88","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":88,"neutrons":53,"relative_atomic_mass":87.9240833,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-89","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":89,"neutrons":54,"relative_atomic_mass":88.9267046,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-90","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":90,"neutrons":55,"relative_atomic_mass":89.9312928,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-91","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":91,"neutrons":56,"relative_atomic_mass":90.9343986,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-92","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":92,"neutrons":57,"relative_atomic_mass":91.9396316,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-93","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":93,"neutrons":58,"relative_atomic_mass":92.94313,"relative_atomic_mass_uncertainty":0.00048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-94","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":94,"neutrons":59,"relative_atomic_mass":93.9489,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-95","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":95,"neutrons":60,"relative_atomic_mass":94.95301,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-96","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":96,"neutrons":61,"relative_atomic_mass":95.95903,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-97","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":97,"neutrons":62,"relative_atomic_mass":96.96344,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Br-98","atomic_number":35,"element_symbol":"Br","nist_symbol":"Br","mass_number":98,"neutrons":63,"relative_atomic_mass":97.96946,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[79.901,79.907]","notes":null},{"isotope":"Kr-69","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":69,"neutrons":33,"relative_atomic_mass":68.96518,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-70","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":70,"neutrons":34,"relative_atomic_mass":69.95604,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-71","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":71,"neutrons":35,"relative_atomic_mass":70.95027,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-72","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":72,"neutrons":36,"relative_atomic_mass":71.9420924,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-73","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":73,"neutrons":37,"relative_atomic_mass":72.9392892,"relative_atomic_mass_uncertainty":0.0000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-74","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":74,"neutrons":38,"relative_atomic_mass":73.933084,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-75","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":75,"neutrons":39,"relative_atomic_mass":74.9309457,"relative_atomic_mass_uncertainty":0.0000087,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-76","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":76,"neutrons":40,"relative_atomic_mass":75.9259103,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-77","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":77,"neutrons":41,"relative_atomic_mass":76.92467,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-78","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":78,"neutrons":42,"relative_atomic_mass":77.92036494,"relative_atomic_mass_uncertainty":7.6e-7,"mass_estimated":false,"natural_abundance":0.00355,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-79","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":79,"neutrons":43,"relative_atomic_mass":78.9200829,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-80","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":80,"neutrons":44,"relative_atomic_mass":79.91637808,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":0.02286,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-81","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":81,"neutrons":45,"relative_atomic_mass":80.9165912,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-82","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":82,"neutrons":46,"relative_atomic_mass":81.91348273,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":0.11593,"natural_abundance_uncertainty":0.00031,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-83","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":83,"neutrons":47,"relative_atomic_mass":82.91412716,"relative_atomic_mass_uncertainty":3.2e-7,"mass_estimated":false,"natural_abundance":0.115,"natural_abundance_uncertainty":0.00019,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-84","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":84,"neutrons":48,"relative_atomic_mass":83.9114977282,"relative_atomic_mass_uncertainty":4.4e-9,"mass_estimated":false,"natural_abundance":0.56987,"natural_abundance_uncertainty":0.00015,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-85","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":85,"neutrons":49,"relative_atomic_mass":84.9125273,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-86","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":86,"neutrons":50,"relative_atomic_mass":85.9106106269,"relative_atomic_mass_uncertainty":4.1e-9,"mass_estimated":false,"natural_abundance":0.17279,"natural_abundance_uncertainty":0.00041,"naturally_occurring":true,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-87","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":87,"neutrons":51,"relative_atomic_mass":86.91335476,"relative_atomic_mass_uncertainty":2.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-88","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":88,"neutrons":52,"relative_atomic_mass":87.9144479,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-89","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":89,"neutrons":53,"relative_atomic_mass":88.9178355,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-90","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":90,"neutrons":54,"relative_atomic_mass":89.9195279,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-91","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":91,"neutrons":55,"relative_atomic_mass":90.9238063,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-92","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":92,"neutrons":56,"relative_atomic_mass":91.9261731,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-93","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":93,"neutrons":57,"relative_atomic_mass":92.9311472,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-94","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":94,"neutrons":58,"relative_atomic_mass":93.93414,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-95","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":95,"neutrons":59,"relative_atomic_mass":94.939711,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-96","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":96,"neutrons":60,"relative_atomic_mass":95.943017,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-97","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":97,"neutrons":61,"relative_atomic_mass":96.94909,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-98","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":98,"neutrons":62,"relative_atomic_mass":97.95243,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-99","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":99,"neutrons":63,"relative_atomic_mass":98.95839,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-100","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":100,"neutrons":64,"relative_atomic_mass":99.96237,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Kr-101","atomic_number":36,"element_symbol":"Kr","nist_symbol":"Kr","mass_number":101,"neutrons":65,"relative_atomic_mass":100.96873,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"83.798(2)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Rb-71","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":71,"neutrons":34,"relative_atomic_mass":70.96532,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-72","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":72,"neutrons":35,"relative_atomic_mass":71.95908,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-73","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":73,"neutrons":36,"relative_atomic_mass":72.95053,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-74","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":74,"neutrons":37,"relative_atomic_mass":73.9442659,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-75","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":75,"neutrons":38,"relative_atomic_mass":74.9385732,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-76","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":76,"neutrons":39,"relative_atomic_mass":75.935073,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-77","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":77,"neutrons":40,"relative_atomic_mass":76.9304016,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-78","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":78,"neutrons":41,"relative_atomic_mass":77.9281419,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-79","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":79,"neutrons":42,"relative_atomic_mass":78.9239899,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-80","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":80,"neutrons":43,"relative_atomic_mass":79.9225164,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-81","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":81,"neutrons":44,"relative_atomic_mass":80.9189939,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-82","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":82,"neutrons":45,"relative_atomic_mass":81.918209,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-83","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":83,"neutrons":46,"relative_atomic_mass":82.9151142,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-84","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":84,"neutrons":47,"relative_atomic_mass":83.9143752,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-85","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":85,"neutrons":48,"relative_atomic_mass":84.9117897379,"relative_atomic_mass_uncertainty":5.4e-9,"mass_estimated":false,"natural_abundance":0.7217,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-86","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":86,"neutrons":49,"relative_atomic_mass":85.91116743,"relative_atomic_mass_uncertainty":2.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-87","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":87,"neutrons":50,"relative_atomic_mass":86.909180531,"relative_atomic_mass_uncertainty":6e-9,"mass_estimated":false,"natural_abundance":0.2783,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-88","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":88,"neutrons":51,"relative_atomic_mass":87.91131559,"relative_atomic_mass_uncertainty":1.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-89","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":89,"neutrons":52,"relative_atomic_mass":88.9122783,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-90","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":90,"neutrons":53,"relative_atomic_mass":89.9147985,"relative_atomic_mass_uncertainty":0.000007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-91","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":91,"neutrons":54,"relative_atomic_mass":90.9165372,"relative_atomic_mass_uncertainty":0.0000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-92","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":92,"neutrons":55,"relative_atomic_mass":91.9197284,"relative_atomic_mass_uncertainty":0.0000066,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-93","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":93,"neutrons":56,"relative_atomic_mass":92.9220393,"relative_atomic_mass_uncertainty":0.0000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-94","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":94,"neutrons":57,"relative_atomic_mass":93.9263948,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-95","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":95,"neutrons":58,"relative_atomic_mass":94.92926,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-96","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":96,"neutrons":59,"relative_atomic_mass":95.9341334,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-97","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":97,"neutrons":60,"relative_atomic_mass":96.9371771,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-98","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":98,"neutrons":61,"relative_atomic_mass":97.9416869,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-99","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":99,"neutrons":62,"relative_atomic_mass":98.94503,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-100","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":100,"neutrons":63,"relative_atomic_mass":99.95003,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-101","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":101,"neutrons":64,"relative_atomic_mass":100.95404,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-102","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":102,"neutrons":65,"relative_atomic_mass":101.95952,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rb-103","atomic_number":37,"element_symbol":"Rb","nist_symbol":"Rb","mass_number":103,"neutrons":66,"relative_atomic_mass":102.96392,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"85.4678(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sr-73","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":73,"neutrons":35,"relative_atomic_mass":72.9657,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-74","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":74,"neutrons":36,"relative_atomic_mass":73.95617,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-75","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":75,"neutrons":37,"relative_atomic_mass":74.94995,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-76","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":76,"neutrons":38,"relative_atomic_mass":75.941763,"relative_atomic_mass_uncertainty":0.000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-77","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":77,"neutrons":39,"relative_atomic_mass":76.9379455,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-78","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":78,"neutrons":40,"relative_atomic_mass":77.93218,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-79","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":79,"neutrons":41,"relative_atomic_mass":78.9297077,"relative_atomic_mass_uncertainty":0.000009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-80","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":80,"neutrons":42,"relative_atomic_mass":79.9245175,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-81","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":81,"neutrons":43,"relative_atomic_mass":80.9232114,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-82","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":82,"neutrons":44,"relative_atomic_mass":81.9183999,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-83","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":83,"neutrons":45,"relative_atomic_mass":82.9175544,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-84","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":84,"neutrons":46,"relative_atomic_mass":83.9134191,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.0056,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-85","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":85,"neutrons":47,"relative_atomic_mass":84.912932,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-86","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":86,"neutrons":48,"relative_atomic_mass":85.9092606,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.0986,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-87","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":87,"neutrons":49,"relative_atomic_mass":86.9088775,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.07,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-88","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":88,"neutrons":50,"relative_atomic_mass":87.9056125,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.8258,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-89","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":89,"neutrons":51,"relative_atomic_mass":88.9074511,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-90","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":90,"neutrons":52,"relative_atomic_mass":89.90773,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-91","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":91,"neutrons":53,"relative_atomic_mass":90.9101954,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-92","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":92,"neutrons":54,"relative_atomic_mass":91.9110382,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-93","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":93,"neutrons":55,"relative_atomic_mass":92.9140242,"relative_atomic_mass_uncertainty":0.0000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-94","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":94,"neutrons":56,"relative_atomic_mass":93.9153556,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-95","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":95,"neutrons":57,"relative_atomic_mass":94.9193529,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-96","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":96,"neutrons":58,"relative_atomic_mass":95.9217066,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-97","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":97,"neutrons":59,"relative_atomic_mass":96.926374,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-98","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":98,"neutrons":60,"relative_atomic_mass":97.9286888,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-99","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":99,"neutrons":61,"relative_atomic_mass":98.9328907,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-100","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":100,"neutrons":62,"relative_atomic_mass":99.93577,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-101","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":101,"neutrons":63,"relative_atomic_mass":100.940352,"relative_atomic_mass_uncertainty":0.000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-102","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":102,"neutrons":64,"relative_atomic_mass":101.943791,"relative_atomic_mass_uncertainty":0.000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-103","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":103,"neutrons":65,"relative_atomic_mass":102.94909,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-104","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":104,"neutrons":66,"relative_atomic_mass":103.95265,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-105","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":105,"neutrons":67,"relative_atomic_mass":104.95855,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-106","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":106,"neutrons":68,"relative_atomic_mass":105.96265,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Sr-107","atomic_number":38,"element_symbol":"Sr","nist_symbol":"Sr","mass_number":107,"neutrons":69,"relative_atomic_mass":106.96897,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"87.62(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Y-76","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":76,"neutrons":37,"relative_atomic_mass":75.95856,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-77","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":77,"neutrons":38,"relative_atomic_mass":76.949781,"relative_atomic_mass_uncertainty":0.000065,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-78","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":78,"neutrons":39,"relative_atomic_mass":77.94361,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-79","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":79,"neutrons":40,"relative_atomic_mass":78.93735,"relative_atomic_mass_uncertainty":0.00048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-80","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":80,"neutrons":41,"relative_atomic_mass":79.9343561,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-81","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":81,"neutrons":42,"relative_atomic_mass":80.9294556,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-82","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":82,"neutrons":43,"relative_atomic_mass":81.9269314,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-83","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":83,"neutrons":44,"relative_atomic_mass":82.922485,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-84","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":84,"neutrons":45,"relative_atomic_mass":83.9206721,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-85","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":85,"neutrons":46,"relative_atomic_mass":84.916433,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-86","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":86,"neutrons":47,"relative_atomic_mass":85.914886,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-87","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":87,"neutrons":48,"relative_atomic_mass":86.9108761,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-88","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":88,"neutrons":49,"relative_atomic_mass":87.9095016,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-89","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":89,"neutrons":50,"relative_atomic_mass":88.9058403,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-90","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":90,"neutrons":51,"relative_atomic_mass":89.9071439,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-91","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":91,"neutrons":52,"relative_atomic_mass":90.9072974,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-92","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":92,"neutrons":53,"relative_atomic_mass":91.9089451,"relative_atomic_mass_uncertainty":0.0000099,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-93","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":93,"neutrons":54,"relative_atomic_mass":92.909578,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-94","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":94,"neutrons":55,"relative_atomic_mass":93.9115906,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-95","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":95,"neutrons":56,"relative_atomic_mass":94.9128161,"relative_atomic_mass_uncertainty":0.0000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-96","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":96,"neutrons":57,"relative_atomic_mass":95.9158968,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-97","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":97,"neutrons":58,"relative_atomic_mass":96.9182741,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-98","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":98,"neutrons":59,"relative_atomic_mass":97.9223821,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-99","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":99,"neutrons":60,"relative_atomic_mass":98.924148,"relative_atomic_mass_uncertainty":0.0000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-100","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":100,"neutrons":61,"relative_atomic_mass":99.927715,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-101","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":101,"neutrons":62,"relative_atomic_mass":100.9301477,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-102","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":102,"neutrons":63,"relative_atomic_mass":101.9343277,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-103","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":103,"neutrons":64,"relative_atomic_mass":102.937243,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-104","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":104,"neutrons":65,"relative_atomic_mass":103.94196,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-105","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":105,"neutrons":66,"relative_atomic_mass":104.94544,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-106","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":106,"neutrons":67,"relative_atomic_mass":105.95056,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-107","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":107,"neutrons":68,"relative_atomic_mass":106.95452,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-108","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":108,"neutrons":69,"relative_atomic_mass":107.95996,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Y-109","atomic_number":39,"element_symbol":"Y","nist_symbol":"Y","mass_number":109,"neutrons":70,"relative_atomic_mass":108.96436,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"88.90584(2)","notes":null},{"isotope":"Zr-78","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":78,"neutrons":38,"relative_atomic_mass":77.95566,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-79","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":79,"neutrons":39,"relative_atomic_mass":78.94948,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-80","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":80,"neutrons":40,"relative_atomic_mass":79.9404,"relative_atomic_mass_uncertainty":0.0016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-81","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":81,"neutrons":41,"relative_atomic_mass":80.93731,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-82","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":82,"neutrons":42,"relative_atomic_mass":81.93135,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-83","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":83,"neutrons":43,"relative_atomic_mass":82.9292421,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-84","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":84,"neutrons":44,"relative_atomic_mass":83.9233269,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-85","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":85,"neutrons":45,"relative_atomic_mass":84.9214444,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-86","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":86,"neutrons":46,"relative_atomic_mass":85.9162972,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-87","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":87,"neutrons":47,"relative_atomic_mass":86.914818,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-88","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":88,"neutrons":48,"relative_atomic_mass":87.9102213,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-89","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":89,"neutrons":49,"relative_atomic_mass":88.9088814,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-90","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":90,"neutrons":50,"relative_atomic_mass":89.9046977,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.5145,"natural_abundance_uncertainty":0.004,"naturally_occurring":true,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-91","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":91,"neutrons":51,"relative_atomic_mass":90.9056396,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.1122,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-92","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":92,"neutrons":52,"relative_atomic_mass":91.9050347,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.1715,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-93","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":93,"neutrons":53,"relative_atomic_mass":92.9064699,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-94","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":94,"neutrons":54,"relative_atomic_mass":93.9063108,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.1738,"natural_abundance_uncertainty":0.0028,"naturally_occurring":true,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-95","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":95,"neutrons":55,"relative_atomic_mass":94.9080385,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-96","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":96,"neutrons":56,"relative_atomic_mass":95.9082714,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":0.028,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-97","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":97,"neutrons":57,"relative_atomic_mass":96.9109512,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-98","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":98,"neutrons":58,"relative_atomic_mass":97.9127289,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-99","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":99,"neutrons":59,"relative_atomic_mass":98.916667,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-100","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":100,"neutrons":60,"relative_atomic_mass":99.9180006,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-101","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":101,"neutrons":61,"relative_atomic_mass":100.921448,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-102","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":102,"neutrons":62,"relative_atomic_mass":101.9231409,"relative_atomic_mass_uncertainty":0.0000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-103","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":103,"neutrons":63,"relative_atomic_mass":102.927191,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-104","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":104,"neutrons":64,"relative_atomic_mass":103.929436,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-105","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":105,"neutrons":65,"relative_atomic_mass":104.934008,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-106","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":106,"neutrons":66,"relative_atomic_mass":105.93676,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-107","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":107,"neutrons":67,"relative_atomic_mass":106.94174,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-108","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":108,"neutrons":68,"relative_atomic_mass":107.94487,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-109","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":109,"neutrons":69,"relative_atomic_mass":108.95041,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-110","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":110,"neutrons":70,"relative_atomic_mass":109.95396,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-111","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":111,"neutrons":71,"relative_atomic_mass":110.95968,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Zr-112","atomic_number":40,"element_symbol":"Zr","nist_symbol":"Zr","mass_number":112,"neutrons":72,"relative_atomic_mass":111.9637,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"91.224(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nb-81","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":81,"neutrons":40,"relative_atomic_mass":80.9496,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-82","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":82,"neutrons":41,"relative_atomic_mass":81.94396,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-83","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":83,"neutrons":42,"relative_atomic_mass":82.93729,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-84","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":84,"neutrons":43,"relative_atomic_mass":83.93449,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-85","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":85,"neutrons":44,"relative_atomic_mass":84.9288458,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-86","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":86,"neutrons":45,"relative_atomic_mass":85.9257828,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-87","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":87,"neutrons":46,"relative_atomic_mass":86.9206937,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-88","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":88,"neutrons":47,"relative_atomic_mass":87.918222,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-89","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":89,"neutrons":48,"relative_atomic_mass":88.913445,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-90","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":90,"neutrons":49,"relative_atomic_mass":89.9112584,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-91","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":91,"neutrons":50,"relative_atomic_mass":90.9069897,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-92","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":92,"neutrons":51,"relative_atomic_mass":91.9071881,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-93","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":93,"neutrons":52,"relative_atomic_mass":92.906373,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-94","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":94,"neutrons":53,"relative_atomic_mass":93.9072788,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-95","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":95,"neutrons":54,"relative_atomic_mass":94.9068324,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-96","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":96,"neutrons":55,"relative_atomic_mass":95.9080973,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-97","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":97,"neutrons":56,"relative_atomic_mass":96.9080959,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-98","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":98,"neutrons":57,"relative_atomic_mass":97.9103265,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-99","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":99,"neutrons":58,"relative_atomic_mass":98.911613,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-100","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":100,"neutrons":59,"relative_atomic_mass":99.9143276,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-101","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":101,"neutrons":60,"relative_atomic_mass":100.9153103,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-102","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":102,"neutrons":61,"relative_atomic_mass":101.9180772,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-103","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":103,"neutrons":62,"relative_atomic_mass":102.9194572,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-104","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":104,"neutrons":63,"relative_atomic_mass":103.9228925,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-105","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":105,"neutrons":64,"relative_atomic_mass":104.9249465,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-106","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":106,"neutrons":65,"relative_atomic_mass":105.9289317,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-107","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":107,"neutrons":66,"relative_atomic_mass":106.9315937,"relative_atomic_mass_uncertainty":0.0000087,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-108","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":108,"neutrons":67,"relative_atomic_mass":107.9360748,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-109","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":109,"neutrons":68,"relative_atomic_mass":108.93922,"relative_atomic_mass_uncertainty":0.00056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-110","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":110,"neutrons":69,"relative_atomic_mass":109.94403,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-111","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":111,"neutrons":70,"relative_atomic_mass":110.94753,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-112","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":112,"neutrons":71,"relative_atomic_mass":111.95247,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-113","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":113,"neutrons":72,"relative_atomic_mass":112.95651,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-114","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":114,"neutrons":73,"relative_atomic_mass":113.96201,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Nb-115","atomic_number":41,"element_symbol":"Nb","nist_symbol":"Nb","mass_number":115,"neutrons":74,"relative_atomic_mass":114.96634,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"92.90637(2)","notes":null},{"isotope":"Mo-83","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":83,"neutrons":41,"relative_atomic_mass":82.94988,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-84","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":84,"neutrons":42,"relative_atomic_mass":83.94149,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-85","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":85,"neutrons":43,"relative_atomic_mass":84.938261,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-86","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":86,"neutrons":44,"relative_atomic_mass":85.9311748,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-87","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":87,"neutrons":45,"relative_atomic_mass":86.9281962,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-88","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":88,"neutrons":46,"relative_atomic_mass":87.9219678,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-89","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":89,"neutrons":47,"relative_atomic_mass":88.9194682,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-90","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":90,"neutrons":48,"relative_atomic_mass":89.9139309,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-91","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":91,"neutrons":49,"relative_atomic_mass":90.9117453,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-92","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":92,"neutrons":50,"relative_atomic_mass":91.90680796,"relative_atomic_mass_uncertainty":8.4e-7,"mass_estimated":false,"natural_abundance":0.1453,"natural_abundance_uncertainty":0.003,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-93","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":93,"neutrons":51,"relative_atomic_mass":92.90680958,"relative_atomic_mass_uncertainty":8.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-94","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":94,"neutrons":52,"relative_atomic_mass":93.9050849,"relative_atomic_mass_uncertainty":4.8e-7,"mass_estimated":false,"natural_abundance":0.0915,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-95","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":95,"neutrons":53,"relative_atomic_mass":94.90583877,"relative_atomic_mass_uncertainty":4.7e-7,"mass_estimated":false,"natural_abundance":0.1584,"natural_abundance_uncertainty":0.0011,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-96","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":96,"neutrons":54,"relative_atomic_mass":95.90467612,"relative_atomic_mass_uncertainty":4.7e-7,"mass_estimated":false,"natural_abundance":0.1667,"natural_abundance_uncertainty":0.0015,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-97","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":97,"neutrons":55,"relative_atomic_mass":96.90601812,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":0.096,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-98","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":98,"neutrons":56,"relative_atomic_mass":97.90540482,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":0.2439,"natural_abundance_uncertainty":0.0037,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-99","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":99,"neutrons":57,"relative_atomic_mass":98.90770851,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-100","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":100,"neutrons":58,"relative_atomic_mass":99.9074718,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.0982,"natural_abundance_uncertainty":0.0031,"naturally_occurring":true,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-101","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":101,"neutrons":59,"relative_atomic_mass":100.9103414,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-102","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":102,"neutrons":60,"relative_atomic_mass":101.9102834,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-103","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":103,"neutrons":61,"relative_atomic_mass":102.913079,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-104","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":104,"neutrons":62,"relative_atomic_mass":103.9137344,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-105","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":105,"neutrons":63,"relative_atomic_mass":104.916969,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-106","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":106,"neutrons":64,"relative_atomic_mass":105.918259,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-107","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":107,"neutrons":65,"relative_atomic_mass":106.922106,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-108","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":108,"neutrons":66,"relative_atomic_mass":107.924033,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-109","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":109,"neutrons":67,"relative_atomic_mass":108.928424,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-110","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":110,"neutrons":68,"relative_atomic_mass":109.930704,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-111","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":111,"neutrons":69,"relative_atomic_mass":110.935654,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-112","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":112,"neutrons":70,"relative_atomic_mass":111.93831,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-113","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":113,"neutrons":71,"relative_atomic_mass":112.94335,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-114","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":114,"neutrons":72,"relative_atomic_mass":113.94653,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-115","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":115,"neutrons":73,"relative_atomic_mass":114.95196,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-116","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":116,"neutrons":74,"relative_atomic_mass":115.95545,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Mo-117","atomic_number":42,"element_symbol":"Mo","nist_symbol":"Mo","mass_number":117,"neutrons":75,"relative_atomic_mass":116.96117,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"95.95(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Tc-85","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":85,"neutrons":42,"relative_atomic_mass":84.95058,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-86","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":86,"neutrons":43,"relative_atomic_mass":85.94493,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-87","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":87,"neutrons":44,"relative_atomic_mass":86.9380672,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-88","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":88,"neutrons":45,"relative_atomic_mass":87.93378,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-89","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":89,"neutrons":46,"relative_atomic_mass":88.9276487,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-90","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":90,"neutrons":47,"relative_atomic_mass":89.9240739,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-91","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":91,"neutrons":48,"relative_atomic_mass":90.9184254,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-92","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":92,"neutrons":49,"relative_atomic_mass":91.9152698,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-93","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":93,"neutrons":50,"relative_atomic_mass":92.910246,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-94","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":94,"neutrons":51,"relative_atomic_mass":93.9096536,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-95","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":95,"neutrons":52,"relative_atomic_mass":94.9076536,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-96","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":96,"neutrons":53,"relative_atomic_mass":95.907868,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-97","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":97,"neutrons":54,"relative_atomic_mass":96.9063667,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-98","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":98,"neutrons":55,"relative_atomic_mass":97.9072124,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-99","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":99,"neutrons":56,"relative_atomic_mass":98.9062508,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-100","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":100,"neutrons":57,"relative_atomic_mass":99.9076539,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-101","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":101,"neutrons":58,"relative_atomic_mass":100.907309,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-102","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":102,"neutrons":59,"relative_atomic_mass":101.9092097,"relative_atomic_mass_uncertainty":0.0000099,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-103","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":103,"neutrons":60,"relative_atomic_mass":102.909176,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-104","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":104,"neutrons":61,"relative_atomic_mass":103.911425,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-105","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":105,"neutrons":62,"relative_atomic_mass":104.911655,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-106","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":106,"neutrons":63,"relative_atomic_mass":105.914358,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-107","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":107,"neutrons":64,"relative_atomic_mass":106.9154606,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-108","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":108,"neutrons":65,"relative_atomic_mass":107.9184957,"relative_atomic_mass_uncertainty":0.0000094,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-109","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":109,"neutrons":66,"relative_atomic_mass":108.920256,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-110","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":110,"neutrons":67,"relative_atomic_mass":109.923744,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-111","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":111,"neutrons":68,"relative_atomic_mass":110.925901,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-112","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":112,"neutrons":69,"relative_atomic_mass":111.9299458,"relative_atomic_mass_uncertainty":0.000006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-113","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":113,"neutrons":70,"relative_atomic_mass":112.932569,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-114","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":114,"neutrons":71,"relative_atomic_mass":113.93691,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-115","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":115,"neutrons":72,"relative_atomic_mass":114.93998,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-116","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":116,"neutrons":73,"relative_atomic_mass":115.94476,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-117","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":117,"neutrons":74,"relative_atomic_mass":116.94806,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-118","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":118,"neutrons":75,"relative_atomic_mass":117.95299,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-119","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":119,"neutrons":76,"relative_atomic_mass":118.95666,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Tc-120","atomic_number":43,"element_symbol":"Tc","nist_symbol":"Tc","mass_number":120,"neutrons":77,"relative_atomic_mass":119.96187,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[98]","notes":null},{"isotope":"Ru-87","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":87,"neutrons":43,"relative_atomic_mass":86.95069,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-88","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":88,"neutrons":44,"relative_atomic_mass":87.9416,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-89","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":89,"neutrons":45,"relative_atomic_mass":88.93762,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-90","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":90,"neutrons":46,"relative_atomic_mass":89.9303444,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-91","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":91,"neutrons":47,"relative_atomic_mass":90.9267419,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-92","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":92,"neutrons":48,"relative_atomic_mass":91.9202344,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-93","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":93,"neutrons":49,"relative_atomic_mass":92.9171044,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-94","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":94,"neutrons":50,"relative_atomic_mass":93.9113429,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-95","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":95,"neutrons":51,"relative_atomic_mass":94.910406,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-96","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":96,"neutrons":52,"relative_atomic_mass":95.90759025,"relative_atomic_mass_uncertainty":4.9e-7,"mass_estimated":false,"natural_abundance":0.0554,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-97","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":97,"neutrons":53,"relative_atomic_mass":96.9075471,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-98","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":98,"neutrons":54,"relative_atomic_mass":97.9052868,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":0.0187,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-99","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":99,"neutrons":55,"relative_atomic_mass":98.9059341,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.1276,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-100","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":100,"neutrons":56,"relative_atomic_mass":99.9042143,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.126,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-101","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":101,"neutrons":57,"relative_atomic_mass":100.9055769,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.1706,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-102","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":102,"neutrons":58,"relative_atomic_mass":101.9043441,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.3155,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-103","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":103,"neutrons":59,"relative_atomic_mass":102.9063186,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-104","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":104,"neutrons":60,"relative_atomic_mass":103.9054275,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":0.1862,"natural_abundance_uncertainty":0.0027,"naturally_occurring":true,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-105","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":105,"neutrons":61,"relative_atomic_mass":104.9077476,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-106","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":106,"neutrons":62,"relative_atomic_mass":105.9073291,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-107","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":107,"neutrons":63,"relative_atomic_mass":106.909972,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-108","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":108,"neutrons":64,"relative_atomic_mass":107.910188,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-109","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":109,"neutrons":65,"relative_atomic_mass":108.913326,"relative_atomic_mass_uncertainty":0.0000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-110","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":110,"neutrons":66,"relative_atomic_mass":109.9140407,"relative_atomic_mass_uncertainty":0.0000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-111","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":111,"neutrons":67,"relative_atomic_mass":110.91757,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-112","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":112,"neutrons":68,"relative_atomic_mass":111.918809,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-113","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":113,"neutrons":69,"relative_atomic_mass":112.922844,"relative_atomic_mass_uncertainty":0.000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-114","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":114,"neutrons":70,"relative_atomic_mass":113.9246136,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-115","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":115,"neutrons":71,"relative_atomic_mass":114.92882,"relative_atomic_mass_uncertainty":0.000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-116","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":116,"neutrons":72,"relative_atomic_mass":115.9312192,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-117","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":117,"neutrons":73,"relative_atomic_mass":116.9361,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-118","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":118,"neutrons":74,"relative_atomic_mass":117.93853,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-119","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":119,"neutrons":75,"relative_atomic_mass":118.94357,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-120","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":120,"neutrons":76,"relative_atomic_mass":119.94631,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-121","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":121,"neutrons":77,"relative_atomic_mass":120.95164,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-122","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":122,"neutrons":78,"relative_atomic_mass":121.95447,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-123","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":123,"neutrons":79,"relative_atomic_mass":122.95989,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ru-124","atomic_number":44,"element_symbol":"Ru","nist_symbol":"Ru","mass_number":124,"neutrons":80,"relative_atomic_mass":123.96305,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"101.07(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Rh-89","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":89,"neutrons":44,"relative_atomic_mass":88.95058,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-90","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":90,"neutrons":45,"relative_atomic_mass":89.94422,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-91","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":91,"neutrons":46,"relative_atomic_mass":90.93688,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-92","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":92,"neutrons":47,"relative_atomic_mass":91.9323677,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-93","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":93,"neutrons":48,"relative_atomic_mass":92.9259128,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-94","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":94,"neutrons":49,"relative_atomic_mass":93.9217305,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-95","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":95,"neutrons":50,"relative_atomic_mass":94.9158979,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-96","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":96,"neutrons":51,"relative_atomic_mass":95.914453,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-97","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":97,"neutrons":52,"relative_atomic_mass":96.911329,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-98","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":98,"neutrons":53,"relative_atomic_mass":97.910708,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-99","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":99,"neutrons":54,"relative_atomic_mass":98.9081282,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-100","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":100,"neutrons":55,"relative_atomic_mass":99.908117,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-101","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":101,"neutrons":56,"relative_atomic_mass":100.9061606,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-102","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":102,"neutrons":57,"relative_atomic_mass":101.9068374,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-103","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":103,"neutrons":58,"relative_atomic_mass":102.905498,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-104","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":104,"neutrons":59,"relative_atomic_mass":103.9066492,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-105","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":105,"neutrons":60,"relative_atomic_mass":104.9056885,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-106","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":106,"neutrons":61,"relative_atomic_mass":105.9072868,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-107","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":107,"neutrons":62,"relative_atomic_mass":106.906748,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-108","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":108,"neutrons":63,"relative_atomic_mass":107.908714,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-109","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":109,"neutrons":64,"relative_atomic_mass":108.9087488,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-110","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":110,"neutrons":65,"relative_atomic_mass":109.911079,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-111","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":111,"neutrons":66,"relative_atomic_mass":110.9116423,"relative_atomic_mass_uncertainty":0.0000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-112","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":112,"neutrons":67,"relative_atomic_mass":111.914403,"relative_atomic_mass_uncertainty":0.000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-113","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":113,"neutrons":68,"relative_atomic_mass":112.9154393,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-114","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":114,"neutrons":69,"relative_atomic_mass":113.918718,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-115","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":115,"neutrons":70,"relative_atomic_mass":114.9203116,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-116","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":116,"neutrons":71,"relative_atomic_mass":115.924059,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-117","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":117,"neutrons":72,"relative_atomic_mass":116.9260354,"relative_atomic_mass_uncertainty":0.0000095,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-118","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":118,"neutrons":73,"relative_atomic_mass":117.93034,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-119","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":119,"neutrons":74,"relative_atomic_mass":118.932557,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-120","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":120,"neutrons":75,"relative_atomic_mass":119.93686,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-121","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":121,"neutrons":76,"relative_atomic_mass":120.93942,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-122","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":122,"neutrons":77,"relative_atomic_mass":121.94399,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-123","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":123,"neutrons":78,"relative_atomic_mass":122.94685,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-124","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":124,"neutrons":79,"relative_atomic_mass":123.95151,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-125","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":125,"neutrons":80,"relative_atomic_mass":124.95469,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Rh-126","atomic_number":45,"element_symbol":"Rh","nist_symbol":"Rh","mass_number":126,"neutrons":81,"relative_atomic_mass":125.95946,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"102.90550(2)","notes":null},{"isotope":"Pd-91","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":91,"neutrons":45,"relative_atomic_mass":90.95032,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-92","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":92,"neutrons":46,"relative_atomic_mass":91.94088,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-93","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":93,"neutrons":47,"relative_atomic_mass":92.93651,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-94","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":94,"neutrons":48,"relative_atomic_mass":93.9290376,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-95","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":95,"neutrons":49,"relative_atomic_mass":94.9248898,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-96","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":96,"neutrons":50,"relative_atomic_mass":95.9182151,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-97","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":97,"neutrons":51,"relative_atomic_mass":96.916472,"relative_atomic_mass_uncertainty":0.0000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-98","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":98,"neutrons":52,"relative_atomic_mass":97.9126983,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-99","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":99,"neutrons":53,"relative_atomic_mass":98.9117748,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-100","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":100,"neutrons":54,"relative_atomic_mass":99.908505,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-101","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":101,"neutrons":55,"relative_atomic_mass":100.9082864,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-102","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":102,"neutrons":56,"relative_atomic_mass":101.9056022,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":0.0102,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-103","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":103,"neutrons":57,"relative_atomic_mass":102.9060809,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-104","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":104,"neutrons":58,"relative_atomic_mass":103.9040305,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.1114,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-105","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":105,"neutrons":59,"relative_atomic_mass":104.9050796,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.2233,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-106","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":106,"neutrons":60,"relative_atomic_mass":105.9034804,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.2733,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-107","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":107,"neutrons":61,"relative_atomic_mass":106.9051282,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-108","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":108,"neutrons":62,"relative_atomic_mass":107.9038916,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.2646,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-109","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":109,"neutrons":63,"relative_atomic_mass":108.9059504,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-110","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":110,"neutrons":64,"relative_atomic_mass":109.9051722,"relative_atomic_mass_uncertainty":7.5e-7,"mass_estimated":false,"natural_abundance":0.1172,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-111","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":111,"neutrons":65,"relative_atomic_mass":110.90768968,"relative_atomic_mass_uncertainty":8.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-112","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":112,"neutrons":66,"relative_atomic_mass":111.9073297,"relative_atomic_mass_uncertainty":0.000007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-113","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":113,"neutrons":67,"relative_atomic_mass":112.910261,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-114","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":114,"neutrons":68,"relative_atomic_mass":113.9103686,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-115","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":115,"neutrons":69,"relative_atomic_mass":114.913659,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-116","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":116,"neutrons":70,"relative_atomic_mass":115.914297,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-117","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":117,"neutrons":71,"relative_atomic_mass":116.9179547,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-118","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":118,"neutrons":72,"relative_atomic_mass":117.9190667,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-119","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":119,"neutrons":73,"relative_atomic_mass":118.9233402,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-120","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":120,"neutrons":74,"relative_atomic_mass":119.9245511,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-121","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":121,"neutrons":75,"relative_atomic_mass":120.9289503,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-122","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":122,"neutrons":76,"relative_atomic_mass":121.930632,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-123","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":123,"neutrons":77,"relative_atomic_mass":122.93514,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-124","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":124,"neutrons":78,"relative_atomic_mass":123.93714,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-125","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":125,"neutrons":79,"relative_atomic_mass":124.94179,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-126","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":126,"neutrons":80,"relative_atomic_mass":125.94416,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-127","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":127,"neutrons":81,"relative_atomic_mass":126.94907,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pd-128","atomic_number":46,"element_symbol":"Pd","nist_symbol":"Pd","mass_number":128,"neutrons":82,"relative_atomic_mass":127.95183,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"106.42(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-93","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":93,"neutrons":46,"relative_atomic_mass":92.95033,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-94","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":94,"neutrons":47,"relative_atomic_mass":93.94373,"relative_atomic_mass_uncertainty":0.00069,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-95","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":95,"neutrons":48,"relative_atomic_mass":94.93602,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-96","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":96,"neutrons":49,"relative_atomic_mass":95.930744,"relative_atomic_mass_uncertainty":0.000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-97","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":97,"neutrons":50,"relative_atomic_mass":96.92397,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-98","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":98,"neutrons":51,"relative_atomic_mass":97.92156,"relative_atomic_mass_uncertainty":0.000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-99","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":99,"neutrons":52,"relative_atomic_mass":98.9176458,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-100","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":100,"neutrons":53,"relative_atomic_mass":99.9161154,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-101","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":101,"neutrons":54,"relative_atomic_mass":100.912684,"relative_atomic_mass_uncertainty":0.0000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-102","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":102,"neutrons":55,"relative_atomic_mass":101.9117047,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-103","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":103,"neutrons":56,"relative_atomic_mass":102.9089631,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-104","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":104,"neutrons":57,"relative_atomic_mass":103.9086239,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-105","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":105,"neutrons":58,"relative_atomic_mass":104.9065256,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-106","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":106,"neutrons":59,"relative_atomic_mass":105.9066636,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-107","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":107,"neutrons":60,"relative_atomic_mass":106.9050916,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":0.51839,"natural_abundance_uncertainty":0.00008,"naturally_occurring":true,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-108","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":108,"neutrons":61,"relative_atomic_mass":107.9059503,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-109","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":109,"neutrons":62,"relative_atomic_mass":108.9047553,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.48161,"natural_abundance_uncertainty":0.00008,"naturally_occurring":true,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-110","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":110,"neutrons":63,"relative_atomic_mass":109.9061102,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-111","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":111,"neutrons":64,"relative_atomic_mass":110.9052959,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-112","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":112,"neutrons":65,"relative_atomic_mass":111.9070486,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-113","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":113,"neutrons":66,"relative_atomic_mass":112.906573,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-114","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":114,"neutrons":67,"relative_atomic_mass":113.908823,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-115","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":115,"neutrons":68,"relative_atomic_mass":114.908767,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-116","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":116,"neutrons":69,"relative_atomic_mass":115.9113868,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-117","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":117,"neutrons":70,"relative_atomic_mass":116.911774,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-118","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":118,"neutrons":71,"relative_atomic_mass":117.9145955,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-119","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":119,"neutrons":72,"relative_atomic_mass":118.91557,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-120","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":120,"neutrons":73,"relative_atomic_mass":119.9187848,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-121","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":121,"neutrons":74,"relative_atomic_mass":120.920125,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-122","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":122,"neutrons":75,"relative_atomic_mass":121.923664,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-123","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":123,"neutrons":76,"relative_atomic_mass":122.925337,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-124","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":124,"neutrons":77,"relative_atomic_mass":123.92893,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-125","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":125,"neutrons":78,"relative_atomic_mass":124.93105,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-126","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":126,"neutrons":79,"relative_atomic_mass":125.93475,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-127","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":127,"neutrons":80,"relative_atomic_mass":126.93711,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-128","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":128,"neutrons":81,"relative_atomic_mass":127.94106,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-129","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":129,"neutrons":82,"relative_atomic_mass":128.94395,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ag-130","atomic_number":47,"element_symbol":"Ag","nist_symbol":"Ag","mass_number":130,"neutrons":83,"relative_atomic_mass":129.9507,"relative_atomic_mass_uncertainty":0.00036,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"107.8682(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-95","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":95,"neutrons":47,"relative_atomic_mass":94.94994,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-96","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":96,"neutrons":48,"relative_atomic_mass":95.94034,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-97","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":97,"neutrons":49,"relative_atomic_mass":96.9351,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-98","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":98,"neutrons":50,"relative_atomic_mass":97.927389,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-99","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":99,"neutrons":51,"relative_atomic_mass":98.9249258,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-100","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":100,"neutrons":52,"relative_atomic_mass":99.9203488,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-101","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":101,"neutrons":53,"relative_atomic_mass":100.9185862,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-102","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":102,"neutrons":54,"relative_atomic_mass":101.914482,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-103","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":103,"neutrons":55,"relative_atomic_mass":102.9134165,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-104","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":104,"neutrons":56,"relative_atomic_mass":103.9098564,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-105","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":105,"neutrons":57,"relative_atomic_mass":104.9094639,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-106","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":106,"neutrons":58,"relative_atomic_mass":105.9064599,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.0125,"natural_abundance_uncertainty":0.0006,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-107","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":107,"neutrons":59,"relative_atomic_mass":106.9066121,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-108","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":108,"neutrons":60,"relative_atomic_mass":107.9041834,"relative_atomic_mass_uncertainty":0.0000012,"mass_estimated":false,"natural_abundance":0.0089,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-109","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":109,"neutrons":61,"relative_atomic_mass":108.9049867,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-110","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":110,"neutrons":62,"relative_atomic_mass":109.90300661,"relative_atomic_mass_uncertainty":6.1e-7,"mass_estimated":false,"natural_abundance":0.1249,"natural_abundance_uncertainty":0.0018,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-111","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":111,"neutrons":63,"relative_atomic_mass":110.90418287,"relative_atomic_mass_uncertainty":6.1e-7,"mass_estimated":false,"natural_abundance":0.128,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-112","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":112,"neutrons":64,"relative_atomic_mass":111.90276287,"relative_atomic_mass_uncertainty":6e-7,"mass_estimated":false,"natural_abundance":0.2413,"natural_abundance_uncertainty":0.0021,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-113","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":113,"neutrons":65,"relative_atomic_mass":112.90440813,"relative_atomic_mass_uncertainty":4.5e-7,"mass_estimated":false,"natural_abundance":0.1222,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-114","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":114,"neutrons":66,"relative_atomic_mass":113.90336509,"relative_atomic_mass_uncertainty":4.3e-7,"mass_estimated":false,"natural_abundance":0.2873,"natural_abundance_uncertainty":0.0042,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-115","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":115,"neutrons":67,"relative_atomic_mass":114.90543751,"relative_atomic_mass_uncertainty":7.7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-116","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":116,"neutrons":68,"relative_atomic_mass":115.90476315,"relative_atomic_mass_uncertainty":1.7e-7,"mass_estimated":false,"natural_abundance":0.0749,"natural_abundance_uncertainty":0.0018,"naturally_occurring":true,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-117","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":117,"neutrons":69,"relative_atomic_mass":116.907226,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-118","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":118,"neutrons":70,"relative_atomic_mass":117.906922,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-119","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":119,"neutrons":71,"relative_atomic_mass":118.909847,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-120","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":120,"neutrons":72,"relative_atomic_mass":119.9098681,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-121","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":121,"neutrons":73,"relative_atomic_mass":120.9129637,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-122","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":122,"neutrons":74,"relative_atomic_mass":121.9134591,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-123","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":123,"neutrons":75,"relative_atomic_mass":122.9168925,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-124","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":124,"neutrons":76,"relative_atomic_mass":123.9176574,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-125","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":125,"neutrons":77,"relative_atomic_mass":124.9212576,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-126","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":126,"neutrons":78,"relative_atomic_mass":125.9224291,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-127","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":127,"neutrons":79,"relative_atomic_mass":126.926472,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-128","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":128,"neutrons":80,"relative_atomic_mass":127.9278129,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-129","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":129,"neutrons":81,"relative_atomic_mass":128.93182,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-130","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":130,"neutrons":82,"relative_atomic_mass":129.93394,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-131","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":131,"neutrons":83,"relative_atomic_mass":130.9406,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-132","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":132,"neutrons":84,"relative_atomic_mass":131.94604,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Cd-133","atomic_number":48,"element_symbol":"Cd","nist_symbol":"Cd","mass_number":133,"neutrons":85,"relative_atomic_mass":132.95285,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"112.414(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"In-97","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":97,"neutrons":48,"relative_atomic_mass":96.94934,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-98","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":98,"neutrons":49,"relative_atomic_mass":97.94214,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-99","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":99,"neutrons":50,"relative_atomic_mass":98.93411,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-100","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":100,"neutrons":51,"relative_atomic_mass":99.93096,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-101","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":101,"neutrons":52,"relative_atomic_mass":100.92634,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-102","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":102,"neutrons":53,"relative_atomic_mass":101.9241071,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-103","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":103,"neutrons":54,"relative_atomic_mass":102.9198819,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-104","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":104,"neutrons":55,"relative_atomic_mass":103.9182145,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-105","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":105,"neutrons":56,"relative_atomic_mass":104.914502,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-106","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":106,"neutrons":57,"relative_atomic_mass":105.913464,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-107","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":107,"neutrons":58,"relative_atomic_mass":106.91029,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-108","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":108,"neutrons":59,"relative_atomic_mass":107.9096935,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-109","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":109,"neutrons":60,"relative_atomic_mass":108.9071514,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-110","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":110,"neutrons":61,"relative_atomic_mass":109.90717,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-111","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":111,"neutrons":62,"relative_atomic_mass":110.9051085,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-112","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":112,"neutrons":63,"relative_atomic_mass":111.9055377,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-113","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":113,"neutrons":64,"relative_atomic_mass":112.90406184,"relative_atomic_mass_uncertainty":9.1e-7,"mass_estimated":false,"natural_abundance":0.0429,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-114","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":114,"neutrons":65,"relative_atomic_mass":113.90491791,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-115","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":115,"neutrons":66,"relative_atomic_mass":114.903878776,"relative_atomic_mass_uncertainty":1.2e-8,"mass_estimated":false,"natural_abundance":0.9571,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-116","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":116,"neutrons":67,"relative_atomic_mass":115.90525999,"relative_atomic_mass_uncertainty":2.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-117","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":117,"neutrons":68,"relative_atomic_mass":116.9045157,"relative_atomic_mass_uncertainty":0.0000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-118","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":118,"neutrons":69,"relative_atomic_mass":117.9063566,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-119","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":119,"neutrons":70,"relative_atomic_mass":118.9058507,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-120","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":120,"neutrons":71,"relative_atomic_mass":119.907967,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-121","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":121,"neutrons":72,"relative_atomic_mass":120.907851,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-122","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":122,"neutrons":73,"relative_atomic_mass":121.910281,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-123","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":123,"neutrons":74,"relative_atomic_mass":122.910434,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-124","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":124,"neutrons":75,"relative_atomic_mass":123.913182,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-125","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":125,"neutrons":76,"relative_atomic_mass":124.913605,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-126","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":126,"neutrons":77,"relative_atomic_mass":125.916507,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-127","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":127,"neutrons":78,"relative_atomic_mass":126.917446,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-128","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":128,"neutrons":79,"relative_atomic_mass":127.9204,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-129","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":129,"neutrons":80,"relative_atomic_mass":128.9218053,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-130","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":130,"neutrons":81,"relative_atomic_mass":129.924977,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-131","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":131,"neutrons":82,"relative_atomic_mass":130.9269715,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-132","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":132,"neutrons":83,"relative_atomic_mass":131.933001,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-133","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":133,"neutrons":84,"relative_atomic_mass":132.93831,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-134","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":134,"neutrons":85,"relative_atomic_mass":133.94454,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"In-135","atomic_number":49,"element_symbol":"In","nist_symbol":"In","mass_number":135,"neutrons":86,"relative_atomic_mass":134.95005,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"114.818(1)","notes":null},{"isotope":"Sn-99","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":99,"neutrons":49,"relative_atomic_mass":98.94853,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-100","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":100,"neutrons":50,"relative_atomic_mass":99.9385,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-101","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":101,"neutrons":51,"relative_atomic_mass":100.93526,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-102","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":102,"neutrons":52,"relative_atomic_mass":101.93029,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-103","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":103,"neutrons":53,"relative_atomic_mass":102.928105,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-104","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":104,"neutrons":54,"relative_atomic_mass":103.9231052,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-105","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":105,"neutrons":55,"relative_atomic_mass":104.9212684,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-106","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":106,"neutrons":56,"relative_atomic_mass":105.9169574,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-107","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":107,"neutrons":57,"relative_atomic_mass":106.9157137,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-108","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":108,"neutrons":58,"relative_atomic_mass":107.9118943,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-109","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":109,"neutrons":59,"relative_atomic_mass":108.9112921,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-110","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":110,"neutrons":60,"relative_atomic_mass":109.907845,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-111","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":111,"neutrons":61,"relative_atomic_mass":110.9077401,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-112","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":112,"neutrons":62,"relative_atomic_mass":111.90482387,"relative_atomic_mass_uncertainty":6.1e-7,"mass_estimated":false,"natural_abundance":0.0097,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-113","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":113,"neutrons":63,"relative_atomic_mass":112.9051757,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-114","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":114,"neutrons":64,"relative_atomic_mass":113.9027827,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":0.0066,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-115","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":115,"neutrons":65,"relative_atomic_mass":114.903344699,"relative_atomic_mass_uncertainty":1.6e-8,"mass_estimated":false,"natural_abundance":0.0034,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-116","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":116,"neutrons":66,"relative_atomic_mass":115.9017428,"relative_atomic_mass_uncertainty":1e-7,"mass_estimated":false,"natural_abundance":0.1454,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-117","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":117,"neutrons":67,"relative_atomic_mass":116.90295398,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":0.0768,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-118","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":118,"neutrons":68,"relative_atomic_mass":117.90160657,"relative_atomic_mass_uncertainty":5.4e-7,"mass_estimated":false,"natural_abundance":0.2422,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-119","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":119,"neutrons":69,"relative_atomic_mass":118.90331117,"relative_atomic_mass_uncertainty":7.8e-7,"mass_estimated":false,"natural_abundance":0.0859,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-120","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":120,"neutrons":70,"relative_atomic_mass":119.90220163,"relative_atomic_mass_uncertainty":9.7e-7,"mass_estimated":false,"natural_abundance":0.3258,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-121","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":121,"neutrons":71,"relative_atomic_mass":120.9042426,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-122","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":122,"neutrons":72,"relative_atomic_mass":121.9034438,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":0.0463,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-123","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":123,"neutrons":73,"relative_atomic_mass":122.9057252,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-124","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":124,"neutrons":74,"relative_atomic_mass":123.9052766,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.0579,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-125","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":125,"neutrons":75,"relative_atomic_mass":124.9077864,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-126","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":126,"neutrons":76,"relative_atomic_mass":125.907659,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-127","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":127,"neutrons":77,"relative_atomic_mass":126.91039,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-128","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":128,"neutrons":78,"relative_atomic_mass":127.910507,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-129","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":129,"neutrons":79,"relative_atomic_mass":128.913465,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-130","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":130,"neutrons":80,"relative_atomic_mass":129.9139738,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-131","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":131,"neutrons":81,"relative_atomic_mass":130.917045,"relative_atomic_mass_uncertainty":0.0000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-132","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":132,"neutrons":82,"relative_atomic_mass":131.9178267,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-133","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":133,"neutrons":83,"relative_atomic_mass":132.9239134,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-134","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":134,"neutrons":84,"relative_atomic_mass":133.9286821,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-135","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":135,"neutrons":85,"relative_atomic_mass":134.9349086,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-136","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":136,"neutrons":86,"relative_atomic_mass":135.93999,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-137","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":137,"neutrons":87,"relative_atomic_mass":136.94655,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sn-138","atomic_number":50,"element_symbol":"Sn","nist_symbol":"Sn","mass_number":138,"neutrons":88,"relative_atomic_mass":137.95184,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"118.710(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-103","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":103,"neutrons":52,"relative_atomic_mass":102.93969,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-104","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":104,"neutrons":53,"relative_atomic_mass":103.93648,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-105","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":105,"neutrons":54,"relative_atomic_mass":104.931276,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-106","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":106,"neutrons":55,"relative_atomic_mass":105.928638,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-107","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":107,"neutrons":56,"relative_atomic_mass":106.9241506,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-108","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":108,"neutrons":57,"relative_atomic_mass":107.9222267,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-109","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":109,"neutrons":58,"relative_atomic_mass":108.9181411,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-110","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":110,"neutrons":59,"relative_atomic_mass":109.9168543,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-111","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":111,"neutrons":60,"relative_atomic_mass":110.9132182,"relative_atomic_mass_uncertainty":0.0000095,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-112","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":112,"neutrons":61,"relative_atomic_mass":111.9124,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-113","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":113,"neutrons":62,"relative_atomic_mass":112.909375,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-114","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":114,"neutrons":63,"relative_atomic_mass":113.90929,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-115","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":115,"neutrons":64,"relative_atomic_mass":114.906598,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-116","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":116,"neutrons":65,"relative_atomic_mass":115.9067931,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-117","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":117,"neutrons":66,"relative_atomic_mass":116.9048415,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-118","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":118,"neutrons":67,"relative_atomic_mass":117.9055321,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-119","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":119,"neutrons":68,"relative_atomic_mass":118.9039455,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-120","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":120,"neutrons":69,"relative_atomic_mass":119.9050794,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-121","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":121,"neutrons":70,"relative_atomic_mass":120.903812,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":0.5721,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-122","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":122,"neutrons":71,"relative_atomic_mass":121.9051699,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-123","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":123,"neutrons":72,"relative_atomic_mass":122.9042132,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":0.4279,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-124","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":124,"neutrons":73,"relative_atomic_mass":123.905935,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-125","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":125,"neutrons":74,"relative_atomic_mass":124.905253,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-126","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":126,"neutrons":75,"relative_atomic_mass":125.907253,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-127","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":127,"neutrons":76,"relative_atomic_mass":126.9069243,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-128","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":128,"neutrons":77,"relative_atomic_mass":127.909146,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-129","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":129,"neutrons":78,"relative_atomic_mass":128.909147,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-130","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":130,"neutrons":79,"relative_atomic_mass":129.911662,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-131","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":131,"neutrons":80,"relative_atomic_mass":130.9119888,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-132","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":132,"neutrons":81,"relative_atomic_mass":131.9145077,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-133","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":133,"neutrons":82,"relative_atomic_mass":132.9152732,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-134","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":134,"neutrons":83,"relative_atomic_mass":133.9205357,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-135","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":135,"neutrons":84,"relative_atomic_mass":134.9251851,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-136","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":136,"neutrons":85,"relative_atomic_mass":135.9307459,"relative_atomic_mass_uncertainty":0.0000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-137","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":137,"neutrons":86,"relative_atomic_mass":136.93555,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-138","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":138,"neutrons":87,"relative_atomic_mass":137.94145,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-139","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":139,"neutrons":88,"relative_atomic_mass":138.94655,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sb-140","atomic_number":51,"element_symbol":"Sb","nist_symbol":"Sb","mass_number":140,"neutrons":89,"relative_atomic_mass":139.95283,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"121.760(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-105","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":105,"neutrons":53,"relative_atomic_mass":104.9433,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-106","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":106,"neutrons":54,"relative_atomic_mass":105.9375,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-107","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":107,"neutrons":55,"relative_atomic_mass":106.935012,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-108","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":108,"neutrons":56,"relative_atomic_mass":107.9293805,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-109","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":109,"neutrons":57,"relative_atomic_mass":108.9273045,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-110","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":110,"neutrons":58,"relative_atomic_mass":109.9224581,"relative_atomic_mass_uncertainty":0.0000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-111","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":111,"neutrons":59,"relative_atomic_mass":110.9210006,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-112","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":112,"neutrons":60,"relative_atomic_mass":111.9167279,"relative_atomic_mass_uncertainty":0.000009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-113","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":113,"neutrons":61,"relative_atomic_mass":112.915891,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-114","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":114,"neutrons":62,"relative_atomic_mass":113.912089,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-115","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":115,"neutrons":63,"relative_atomic_mass":114.911902,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-116","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":116,"neutrons":64,"relative_atomic_mass":115.90846,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-117","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":117,"neutrons":65,"relative_atomic_mass":116.908646,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-118","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":118,"neutrons":66,"relative_atomic_mass":117.905854,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-119","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":119,"neutrons":67,"relative_atomic_mass":118.9064071,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-120","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":120,"neutrons":68,"relative_atomic_mass":119.9040593,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":0.0009,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-121","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":121,"neutrons":69,"relative_atomic_mass":120.904944,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-122","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":122,"neutrons":70,"relative_atomic_mass":121.9030435,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0255,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-123","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":123,"neutrons":71,"relative_atomic_mass":122.9042698,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0089,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-124","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":124,"neutrons":72,"relative_atomic_mass":123.9028171,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0474,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-125","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":125,"neutrons":73,"relative_atomic_mass":124.9044299,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0707,"natural_abundance_uncertainty":0.0015,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-126","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":126,"neutrons":74,"relative_atomic_mass":125.9033109,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.1884,"natural_abundance_uncertainty":0.0025,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-127","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":127,"neutrons":75,"relative_atomic_mass":126.9052257,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-128","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":128,"neutrons":76,"relative_atomic_mass":127.90446128,"relative_atomic_mass_uncertainty":9.3e-7,"mass_estimated":false,"natural_abundance":0.3174,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-129","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":129,"neutrons":77,"relative_atomic_mass":128.90659646,"relative_atomic_mass_uncertainty":9.3e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-130","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":130,"neutrons":78,"relative_atomic_mass":129.906222748,"relative_atomic_mass_uncertainty":1.2e-8,"mass_estimated":false,"natural_abundance":0.3408,"natural_abundance_uncertainty":0.0062,"naturally_occurring":true,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-131","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":131,"neutrons":79,"relative_atomic_mass":130.908522213,"relative_atomic_mass_uncertainty":6.5e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-132","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":132,"neutrons":80,"relative_atomic_mass":131.9085467,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-133","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":133,"neutrons":81,"relative_atomic_mass":132.9109688,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-134","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":134,"neutrons":82,"relative_atomic_mass":133.911394,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-135","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":135,"neutrons":83,"relative_atomic_mass":134.9165557,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-136","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":136,"neutrons":84,"relative_atomic_mass":135.9201006,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-137","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":137,"neutrons":85,"relative_atomic_mass":136.9255989,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-138","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":138,"neutrons":86,"relative_atomic_mass":137.9294722,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-139","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":139,"neutrons":87,"relative_atomic_mass":138.9353672,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-140","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":140,"neutrons":88,"relative_atomic_mass":139.939499,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-141","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":141,"neutrons":89,"relative_atomic_mass":140.9458,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-142","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":142,"neutrons":90,"relative_atomic_mass":141.95022,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Te-143","atomic_number":52,"element_symbol":"Te","nist_symbol":"Te","mass_number":143,"neutrons":91,"relative_atomic_mass":142.95676,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"127.60(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"I-107","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":107,"neutrons":54,"relative_atomic_mass":106.94678,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-108","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":108,"neutrons":55,"relative_atomic_mass":107.94348,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-109","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":109,"neutrons":56,"relative_atomic_mass":108.9380853,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-110","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":110,"neutrons":57,"relative_atomic_mass":109.935089,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-111","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":111,"neutrons":58,"relative_atomic_mass":110.9302692,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-112","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":112,"neutrons":59,"relative_atomic_mass":111.928005,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-113","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":113,"neutrons":60,"relative_atomic_mass":112.9236501,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-114","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":114,"neutrons":61,"relative_atomic_mass":113.92185,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-115","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":115,"neutrons":62,"relative_atomic_mass":114.918048,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-116","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":116,"neutrons":63,"relative_atomic_mass":115.91681,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-117","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":117,"neutrons":64,"relative_atomic_mass":116.913648,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-118","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":118,"neutrons":65,"relative_atomic_mass":117.913074,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-119","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":119,"neutrons":66,"relative_atomic_mass":118.910074,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-120","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":120,"neutrons":67,"relative_atomic_mass":119.910087,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-121","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":121,"neutrons":68,"relative_atomic_mass":120.9074051,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-122","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":122,"neutrons":69,"relative_atomic_mass":121.9075888,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-123","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":123,"neutrons":70,"relative_atomic_mass":122.9055885,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-124","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":124,"neutrons":71,"relative_atomic_mass":123.906209,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-125","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":125,"neutrons":72,"relative_atomic_mass":124.9046294,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-126","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":126,"neutrons":73,"relative_atomic_mass":125.9056233,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-127","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":127,"neutrons":74,"relative_atomic_mass":126.9044719,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-128","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":128,"neutrons":75,"relative_atomic_mass":127.9058086,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-129","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":129,"neutrons":76,"relative_atomic_mass":128.9049837,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-130","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":130,"neutrons":77,"relative_atomic_mass":129.9066702,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-131","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":131,"neutrons":78,"relative_atomic_mass":130.9061263,"relative_atomic_mass_uncertainty":6.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-132","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":132,"neutrons":79,"relative_atomic_mass":131.9079935,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-133","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":133,"neutrons":80,"relative_atomic_mass":132.907797,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-134","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":134,"neutrons":81,"relative_atomic_mass":133.9097588,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-135","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":135,"neutrons":82,"relative_atomic_mass":134.9100488,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-136","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":136,"neutrons":83,"relative_atomic_mass":135.914604,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-137","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":137,"neutrons":84,"relative_atomic_mass":136.9180282,"relative_atomic_mass_uncertainty":0.000009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-138","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":138,"neutrons":85,"relative_atomic_mass":137.9227264,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-139","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":139,"neutrons":86,"relative_atomic_mass":138.926506,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-140","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":140,"neutrons":87,"relative_atomic_mass":139.93173,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-141","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":141,"neutrons":88,"relative_atomic_mass":140.93569,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-142","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":142,"neutrons":89,"relative_atomic_mass":141.9412,"relative_atomic_mass_uncertainty":0.0004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-143","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":143,"neutrons":90,"relative_atomic_mass":142.94565,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-144","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":144,"neutrons":91,"relative_atomic_mass":143.95139,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"I-145","atomic_number":53,"element_symbol":"I","nist_symbol":"I","mass_number":145,"neutrons":92,"relative_atomic_mass":144.95605,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"126.90447(3)","notes":null},{"isotope":"Xe-109","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":109,"neutrons":55,"relative_atomic_mass":108.95043,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-110","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":110,"neutrons":56,"relative_atomic_mass":109.94426,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-111","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":111,"neutrons":57,"relative_atomic_mass":110.941607,"relative_atomic_mass_uncertainty":0.000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-112","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":112,"neutrons":58,"relative_atomic_mass":111.935559,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-113","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":113,"neutrons":59,"relative_atomic_mass":112.9332217,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-114","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":114,"neutrons":60,"relative_atomic_mass":113.92798,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-115","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":115,"neutrons":61,"relative_atomic_mass":114.926294,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-116","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":116,"neutrons":62,"relative_atomic_mass":115.921581,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-117","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":117,"neutrons":63,"relative_atomic_mass":116.920359,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-118","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":118,"neutrons":64,"relative_atomic_mass":117.916179,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-119","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":119,"neutrons":65,"relative_atomic_mass":118.915411,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-120","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":120,"neutrons":66,"relative_atomic_mass":119.911784,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-121","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":121,"neutrons":67,"relative_atomic_mass":120.911453,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-122","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":122,"neutrons":68,"relative_atomic_mass":121.908368,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-123","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":123,"neutrons":69,"relative_atomic_mass":122.908482,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-124","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":124,"neutrons":70,"relative_atomic_mass":123.905892,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":0.000952,"natural_abundance_uncertainty":0.000003,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-125","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":125,"neutrons":71,"relative_atomic_mass":124.9063944,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-126","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":126,"neutrons":72,"relative_atomic_mass":125.9042983,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":0.00089,"natural_abundance_uncertainty":0.000002,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-127","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":127,"neutrons":73,"relative_atomic_mass":126.9051829,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-128","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":128,"neutrons":74,"relative_atomic_mass":127.903531,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.019102,"natural_abundance_uncertainty":0.000008,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-129","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":129,"neutrons":75,"relative_atomic_mass":128.9047808611,"relative_atomic_mass_uncertainty":6e-9,"mass_estimated":false,"natural_abundance":0.264006,"natural_abundance_uncertainty":0.000082,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-130","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":130,"neutrons":76,"relative_atomic_mass":129.903509349,"relative_atomic_mass_uncertainty":1e-8,"mass_estimated":false,"natural_abundance":0.04071,"natural_abundance_uncertainty":0.000013,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-131","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":131,"neutrons":77,"relative_atomic_mass":130.90508406,"relative_atomic_mass_uncertainty":2.4e-7,"mass_estimated":false,"natural_abundance":0.212324,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-132","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":132,"neutrons":78,"relative_atomic_mass":131.9041550856,"relative_atomic_mass_uncertainty":5.6e-9,"mass_estimated":false,"natural_abundance":0.269086,"natural_abundance_uncertainty":0.000033,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-133","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":133,"neutrons":79,"relative_atomic_mass":132.9059108,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-134","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":134,"neutrons":80,"relative_atomic_mass":133.90539466,"relative_atomic_mass_uncertainty":9e-7,"mass_estimated":false,"natural_abundance":0.104357,"natural_abundance_uncertainty":0.000021,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-135","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":135,"neutrons":81,"relative_atomic_mass":134.9072278,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-136","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":136,"neutrons":82,"relative_atomic_mass":135.907214484,"relative_atomic_mass_uncertainty":1.1e-8,"mass_estimated":false,"natural_abundance":0.088573,"natural_abundance_uncertainty":0.000044,"naturally_occurring":true,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-137","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":137,"neutrons":83,"relative_atomic_mass":136.91155778,"relative_atomic_mass_uncertainty":1.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-138","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":138,"neutrons":84,"relative_atomic_mass":137.9141463,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-139","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":139,"neutrons":85,"relative_atomic_mass":138.9187922,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-140","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":140,"neutrons":86,"relative_atomic_mass":139.9216458,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-141","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":141,"neutrons":87,"relative_atomic_mass":140.9267872,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-142","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":142,"neutrons":88,"relative_atomic_mass":141.9299731,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-143","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":143,"neutrons":89,"relative_atomic_mass":142.9353696,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-144","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":144,"neutrons":90,"relative_atomic_mass":143.9389451,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-145","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":145,"neutrons":91,"relative_atomic_mass":144.94472,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-146","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":146,"neutrons":92,"relative_atomic_mass":145.948518,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-147","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":147,"neutrons":93,"relative_atomic_mass":146.95426,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Xe-148","atomic_number":54,"element_symbol":"Xe","nist_symbol":"Xe","mass_number":148,"neutrons":94,"relative_atomic_mass":147.95813,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"131.293(6)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Cs-112","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":112,"neutrons":57,"relative_atomic_mass":111.950309,"relative_atomic_mass_uncertainty":0.000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-113","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":113,"neutrons":58,"relative_atomic_mass":112.9444291,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-114","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":114,"neutrons":59,"relative_atomic_mass":113.941296,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-115","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":115,"neutrons":60,"relative_atomic_mass":114.93591,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-116","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":116,"neutrons":61,"relative_atomic_mass":115.93337,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-117","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":117,"neutrons":62,"relative_atomic_mass":116.928617,"relative_atomic_mass_uncertainty":0.000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-118","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":118,"neutrons":63,"relative_atomic_mass":117.92656,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-119","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":119,"neutrons":64,"relative_atomic_mass":118.922377,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-120","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":120,"neutrons":65,"relative_atomic_mass":119.920677,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-121","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":121,"neutrons":66,"relative_atomic_mass":120.917227,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-122","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":122,"neutrons":67,"relative_atomic_mass":121.916108,"relative_atomic_mass_uncertainty":0.000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-123","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":123,"neutrons":68,"relative_atomic_mass":122.912996,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-124","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":124,"neutrons":69,"relative_atomic_mass":123.9122578,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-125","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":125,"neutrons":70,"relative_atomic_mass":124.909728,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-126","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":126,"neutrons":71,"relative_atomic_mass":125.909446,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-127","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":127,"neutrons":72,"relative_atomic_mass":126.9074174,"relative_atomic_mass_uncertainty":0.000006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-128","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":128,"neutrons":73,"relative_atomic_mass":127.9077487,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-129","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":129,"neutrons":74,"relative_atomic_mass":128.9060657,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-130","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":130,"neutrons":75,"relative_atomic_mass":129.9067093,"relative_atomic_mass_uncertainty":0.000009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-131","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":131,"neutrons":76,"relative_atomic_mass":130.9054649,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-132","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":132,"neutrons":77,"relative_atomic_mass":131.9064339,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-133","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":133,"neutrons":78,"relative_atomic_mass":132.905451961,"relative_atomic_mass_uncertainty":8e-9,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-134","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":134,"neutrons":79,"relative_atomic_mass":133.906718503,"relative_atomic_mass_uncertainty":1.7e-8,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-135","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":135,"neutrons":80,"relative_atomic_mass":134.905977,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-136","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":136,"neutrons":81,"relative_atomic_mass":135.9073114,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-137","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":137,"neutrons":82,"relative_atomic_mass":136.90708923,"relative_atomic_mass_uncertainty":3.6e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-138","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":138,"neutrons":83,"relative_atomic_mass":137.9110171,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-139","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":139,"neutrons":84,"relative_atomic_mass":138.9133638,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-140","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":140,"neutrons":85,"relative_atomic_mass":139.9172831,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-141","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":141,"neutrons":86,"relative_atomic_mass":140.9200455,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-142","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":142,"neutrons":87,"relative_atomic_mass":141.924296,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-143","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":143,"neutrons":88,"relative_atomic_mass":142.927349,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-144","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":144,"neutrons":89,"relative_atomic_mass":143.932076,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-145","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":145,"neutrons":90,"relative_atomic_mass":144.935527,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-146","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":146,"neutrons":91,"relative_atomic_mass":145.940344,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-147","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":147,"neutrons":92,"relative_atomic_mass":146.944156,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-148","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":148,"neutrons":93,"relative_atomic_mass":147.94923,"relative_atomic_mass_uncertainty":0.00062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-149","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":149,"neutrons":94,"relative_atomic_mass":148.95302,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-150","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":150,"neutrons":95,"relative_atomic_mass":149.95833,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Cs-151","atomic_number":55,"element_symbol":"Cs","nist_symbol":"Cs","mass_number":151,"neutrons":96,"relative_atomic_mass":150.96258,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"132.90545196(6)","notes":null},{"isotope":"Ba-114","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":114,"neutrons":58,"relative_atomic_mass":113.95066,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-115","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":115,"neutrons":59,"relative_atomic_mass":114.94737,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-116","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":116,"neutrons":60,"relative_atomic_mass":115.94128,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-117","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":117,"neutrons":61,"relative_atomic_mass":116.93814,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-118","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":118,"neutrons":62,"relative_atomic_mass":117.93306,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-119","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":119,"neutrons":63,"relative_atomic_mass":118.93066,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-120","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":120,"neutrons":64,"relative_atomic_mass":119.92605,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-121","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":121,"neutrons":65,"relative_atomic_mass":120.92405,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-122","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":122,"neutrons":66,"relative_atomic_mass":121.919904,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-123","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":123,"neutrons":67,"relative_atomic_mass":122.918781,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-124","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":124,"neutrons":68,"relative_atomic_mass":123.915094,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-125","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":125,"neutrons":69,"relative_atomic_mass":124.914472,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-126","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":126,"neutrons":70,"relative_atomic_mass":125.91125,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-127","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":127,"neutrons":71,"relative_atomic_mass":126.911091,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-128","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":128,"neutrons":72,"relative_atomic_mass":127.908342,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-129","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":129,"neutrons":73,"relative_atomic_mass":128.908681,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-130","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":130,"neutrons":74,"relative_atomic_mass":129.9063207,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":0.00106,"natural_abundance_uncertainty":0.00001,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-131","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":131,"neutrons":75,"relative_atomic_mass":130.906941,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-132","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":132,"neutrons":76,"relative_atomic_mass":131.9050611,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":0.00101,"natural_abundance_uncertainty":0.00001,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-133","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":133,"neutrons":77,"relative_atomic_mass":132.9060074,"relative_atomic_mass_uncertainty":0.0000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-134","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":134,"neutrons":78,"relative_atomic_mass":133.90450818,"relative_atomic_mass_uncertainty":3e-7,"mass_estimated":false,"natural_abundance":0.02417,"natural_abundance_uncertainty":0.00018,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-135","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":135,"neutrons":79,"relative_atomic_mass":134.90568838,"relative_atomic_mass_uncertainty":2.9e-7,"mass_estimated":false,"natural_abundance":0.06592,"natural_abundance_uncertainty":0.00012,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-136","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":136,"neutrons":80,"relative_atomic_mass":135.90457573,"relative_atomic_mass_uncertainty":2.9e-7,"mass_estimated":false,"natural_abundance":0.07854,"natural_abundance_uncertainty":0.00024,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-137","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":137,"neutrons":81,"relative_atomic_mass":136.90582714,"relative_atomic_mass_uncertainty":3e-7,"mass_estimated":false,"natural_abundance":0.11232,"natural_abundance_uncertainty":0.00024,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-138","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":138,"neutrons":82,"relative_atomic_mass":137.905247,"relative_atomic_mass_uncertainty":3.1e-7,"mass_estimated":false,"natural_abundance":0.71698,"natural_abundance_uncertainty":0.00042,"naturally_occurring":true,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-139","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":139,"neutrons":83,"relative_atomic_mass":138.9088411,"relative_atomic_mass_uncertainty":3.1e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-140","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":140,"neutrons":84,"relative_atomic_mass":139.9106057,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-141","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":141,"neutrons":85,"relative_atomic_mass":140.9144033,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-142","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":142,"neutrons":86,"relative_atomic_mass":141.9164324,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-143","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":143,"neutrons":87,"relative_atomic_mass":142.9206253,"relative_atomic_mass_uncertainty":0.0000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-144","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":144,"neutrons":88,"relative_atomic_mass":143.9229549,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-145","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":145,"neutrons":89,"relative_atomic_mass":144.9275184,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-146","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":146,"neutrons":90,"relative_atomic_mass":145.930284,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-147","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":147,"neutrons":91,"relative_atomic_mass":146.935304,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-148","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":148,"neutrons":92,"relative_atomic_mass":147.938171,"relative_atomic_mass_uncertainty":0.000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-149","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":149,"neutrons":93,"relative_atomic_mass":148.94308,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-150","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":150,"neutrons":94,"relative_atomic_mass":149.94605,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-151","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":151,"neutrons":95,"relative_atomic_mass":150.95127,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-152","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":152,"neutrons":96,"relative_atomic_mass":151.95481,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"Ba-153","atomic_number":56,"element_symbol":"Ba","nist_symbol":"Ba","mass_number":153,"neutrons":97,"relative_atomic_mass":152.96036,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"137.327(7)","notes":null},{"isotope":"La-116","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":116,"neutrons":59,"relative_atomic_mass":115.9563,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-117","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":117,"neutrons":60,"relative_atomic_mass":116.94999,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-118","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":118,"neutrons":61,"relative_atomic_mass":117.94673,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-119","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":119,"neutrons":62,"relative_atomic_mass":118.94099,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-120","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":120,"neutrons":63,"relative_atomic_mass":119.93807,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-121","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":121,"neutrons":64,"relative_atomic_mass":120.93315,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-122","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":122,"neutrons":65,"relative_atomic_mass":121.93071,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-123","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":123,"neutrons":66,"relative_atomic_mass":122.9263,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-124","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":124,"neutrons":67,"relative_atomic_mass":123.924574,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-125","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":125,"neutrons":68,"relative_atomic_mass":124.920816,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-126","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":126,"neutrons":69,"relative_atomic_mass":125.919513,"relative_atomic_mass_uncertainty":0.000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-127","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":127,"neutrons":70,"relative_atomic_mass":126.916375,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-128","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":128,"neutrons":71,"relative_atomic_mass":127.915592,"relative_atomic_mass_uncertainty":0.000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-129","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":129,"neutrons":72,"relative_atomic_mass":128.912694,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-130","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":130,"neutrons":73,"relative_atomic_mass":129.912369,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-131","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":131,"neutrons":74,"relative_atomic_mass":130.91007,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-132","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":132,"neutrons":75,"relative_atomic_mass":131.910119,"relative_atomic_mass_uncertainty":0.000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-133","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":133,"neutrons":76,"relative_atomic_mass":132.908218,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-134","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":134,"neutrons":77,"relative_atomic_mass":133.908514,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-135","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":135,"neutrons":78,"relative_atomic_mass":134.906984,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-136","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":136,"neutrons":79,"relative_atomic_mass":135.907635,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-137","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":137,"neutrons":80,"relative_atomic_mass":136.9064504,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-138","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":138,"neutrons":81,"relative_atomic_mass":137.9071149,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":0.0008881,"natural_abundance_uncertainty":0.0000071,"naturally_occurring":true,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-139","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":139,"neutrons":82,"relative_atomic_mass":138.9063563,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":0.9991119,"natural_abundance_uncertainty":0.0000071,"naturally_occurring":true,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-140","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":140,"neutrons":83,"relative_atomic_mass":139.9094806,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-141","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":141,"neutrons":84,"relative_atomic_mass":140.910966,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-142","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":142,"neutrons":85,"relative_atomic_mass":141.9140909,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-143","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":143,"neutrons":86,"relative_atomic_mass":142.9160795,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-144","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":144,"neutrons":87,"relative_atomic_mass":143.919646,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-145","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":145,"neutrons":88,"relative_atomic_mass":144.921808,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-146","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":146,"neutrons":89,"relative_atomic_mass":145.925875,"relative_atomic_mass_uncertainty":0.000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-147","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":147,"neutrons":90,"relative_atomic_mass":146.928418,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-148","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":148,"neutrons":91,"relative_atomic_mass":147.932679,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-149","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":149,"neutrons":92,"relative_atomic_mass":148.93535,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-150","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":150,"neutrons":93,"relative_atomic_mass":149.93947,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-151","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":151,"neutrons":94,"relative_atomic_mass":150.94232,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-152","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":152,"neutrons":95,"relative_atomic_mass":151.94682,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-153","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":153,"neutrons":96,"relative_atomic_mass":152.95036,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-154","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":154,"neutrons":97,"relative_atomic_mass":153.95517,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"La-155","atomic_number":57,"element_symbol":"La","nist_symbol":"La","mass_number":155,"neutrons":98,"relative_atomic_mass":154.95901,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"138.90547(7)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-119","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":119,"neutrons":61,"relative_atomic_mass":118.95271,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-120","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":120,"neutrons":62,"relative_atomic_mass":119.94654,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-121","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":121,"neutrons":63,"relative_atomic_mass":120.94335,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-122","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":122,"neutrons":64,"relative_atomic_mass":121.93787,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-123","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":123,"neutrons":65,"relative_atomic_mass":122.93528,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-124","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":124,"neutrons":66,"relative_atomic_mass":123.93031,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-125","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":125,"neutrons":67,"relative_atomic_mass":124.92844,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-126","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":126,"neutrons":68,"relative_atomic_mass":125.923971,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-127","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":127,"neutrons":69,"relative_atomic_mass":126.922727,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-128","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":128,"neutrons":70,"relative_atomic_mass":127.918911,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-129","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":129,"neutrons":71,"relative_atomic_mass":128.918102,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-130","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":130,"neutrons":72,"relative_atomic_mass":129.914736,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-131","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":131,"neutrons":73,"relative_atomic_mass":130.914429,"relative_atomic_mass_uncertainty":0.000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-132","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":132,"neutrons":74,"relative_atomic_mass":131.911464,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-133","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":133,"neutrons":75,"relative_atomic_mass":132.91152,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-134","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":134,"neutrons":76,"relative_atomic_mass":133.908928,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-135","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":135,"neutrons":77,"relative_atomic_mass":134.909161,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-136","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":136,"neutrons":78,"relative_atomic_mass":135.90712921,"relative_atomic_mass_uncertainty":4.1e-7,"mass_estimated":false,"natural_abundance":0.00185,"natural_abundance_uncertainty":0.00002,"naturally_occurring":true,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-137","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":137,"neutrons":79,"relative_atomic_mass":136.90776236,"relative_atomic_mass_uncertainty":4.5e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-138","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":138,"neutrons":80,"relative_atomic_mass":137.905991,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":0.00251,"natural_abundance_uncertainty":0.00002,"naturally_occurring":true,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-139","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":139,"neutrons":81,"relative_atomic_mass":138.9066551,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-140","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":140,"neutrons":82,"relative_atomic_mass":139.9054431,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":0.8845,"natural_abundance_uncertainty":0.00051,"naturally_occurring":true,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-141","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":141,"neutrons":83,"relative_atomic_mass":140.9082807,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-142","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":142,"neutrons":84,"relative_atomic_mass":141.9092504,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":0.11114,"natural_abundance_uncertainty":0.00051,"naturally_occurring":true,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-143","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":143,"neutrons":85,"relative_atomic_mass":142.9123921,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-144","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":144,"neutrons":86,"relative_atomic_mass":143.9136529,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-145","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":145,"neutrons":87,"relative_atomic_mass":144.917265,"relative_atomic_mass_uncertainty":0.000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-146","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":146,"neutrons":88,"relative_atomic_mass":145.918802,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-147","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":147,"neutrons":89,"relative_atomic_mass":146.9226899,"relative_atomic_mass_uncertainty":0.0000092,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-148","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":148,"neutrons":90,"relative_atomic_mass":147.924424,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-149","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":149,"neutrons":91,"relative_atomic_mass":148.928427,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-150","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":150,"neutrons":92,"relative_atomic_mass":149.930384,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-151","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":151,"neutrons":93,"relative_atomic_mass":150.934272,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-152","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":152,"neutrons":94,"relative_atomic_mass":151.9366,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-153","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":153,"neutrons":95,"relative_atomic_mass":152.94093,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-154","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":154,"neutrons":96,"relative_atomic_mass":153.9438,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-155","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":155,"neutrons":97,"relative_atomic_mass":154.94855,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-156","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":156,"neutrons":98,"relative_atomic_mass":155.95183,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ce-157","atomic_number":58,"element_symbol":"Ce","nist_symbol":"Ce","mass_number":157,"neutrons":99,"relative_atomic_mass":156.95705,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.116(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pr-121","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":121,"neutrons":62,"relative_atomic_mass":120.95532,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-122","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":122,"neutrons":63,"relative_atomic_mass":121.95175,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-123","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":123,"neutrons":64,"relative_atomic_mass":122.94596,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-124","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":124,"neutrons":65,"relative_atomic_mass":123.94294,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-125","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":125,"neutrons":66,"relative_atomic_mass":124.9377,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-126","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":126,"neutrons":67,"relative_atomic_mass":125.93524,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-127","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":127,"neutrons":68,"relative_atomic_mass":126.93071,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-128","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":128,"neutrons":69,"relative_atomic_mass":127.928791,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-129","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":129,"neutrons":70,"relative_atomic_mass":128.925095,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-130","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":130,"neutrons":71,"relative_atomic_mass":129.92359,"relative_atomic_mass_uncertainty":0.000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-131","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":131,"neutrons":72,"relative_atomic_mass":130.920235,"relative_atomic_mass_uncertainty":0.00005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-132","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":132,"neutrons":73,"relative_atomic_mass":131.919255,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-133","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":133,"neutrons":74,"relative_atomic_mass":132.916331,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-134","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":134,"neutrons":75,"relative_atomic_mass":133.915697,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-135","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":135,"neutrons":76,"relative_atomic_mass":134.913112,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-136","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":136,"neutrons":77,"relative_atomic_mass":135.912677,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-137","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":137,"neutrons":78,"relative_atomic_mass":136.9106792,"relative_atomic_mass_uncertainty":0.0000087,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-138","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":138,"neutrons":79,"relative_atomic_mass":137.910754,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-139","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":139,"neutrons":80,"relative_atomic_mass":138.9089408,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-140","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":140,"neutrons":81,"relative_atomic_mass":139.9090803,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-141","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":141,"neutrons":82,"relative_atomic_mass":140.9076576,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-142","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":142,"neutrons":83,"relative_atomic_mass":141.9100496,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-143","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":143,"neutrons":84,"relative_atomic_mass":142.9108228,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-144","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":144,"neutrons":85,"relative_atomic_mass":143.9133109,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-145","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":145,"neutrons":86,"relative_atomic_mass":144.9145182,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-146","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":146,"neutrons":87,"relative_atomic_mass":145.91768,"relative_atomic_mass_uncertainty":0.000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-147","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":147,"neutrons":88,"relative_atomic_mass":146.919008,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-148","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":148,"neutrons":89,"relative_atomic_mass":147.92213,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-149","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":149,"neutrons":90,"relative_atomic_mass":148.923736,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-150","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":150,"neutrons":91,"relative_atomic_mass":149.9266765,"relative_atomic_mass_uncertainty":0.0000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-151","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":151,"neutrons":92,"relative_atomic_mass":150.928309,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-152","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":152,"neutrons":93,"relative_atomic_mass":151.931553,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-153","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":153,"neutrons":94,"relative_atomic_mass":152.933904,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-154","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":154,"neutrons":95,"relative_atomic_mass":153.93753,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-155","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":155,"neutrons":96,"relative_atomic_mass":154.940509,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-156","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":156,"neutrons":97,"relative_atomic_mass":155.94464,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-157","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":157,"neutrons":98,"relative_atomic_mass":156.94789,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-158","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":158,"neutrons":99,"relative_atomic_mass":157.95241,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Pr-159","atomic_number":59,"element_symbol":"Pr","nist_symbol":"Pr","mass_number":159,"neutrons":100,"relative_atomic_mass":158.95589,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"140.90766(2)","notes":null},{"isotope":"Nd-124","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":124,"neutrons":64,"relative_atomic_mass":123.9522,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-125","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":125,"neutrons":65,"relative_atomic_mass":124.9489,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-126","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":126,"neutrons":66,"relative_atomic_mass":125.94311,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-127","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":127,"neutrons":67,"relative_atomic_mass":126.94038,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-128","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":128,"neutrons":68,"relative_atomic_mass":127.93525,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-129","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":129,"neutrons":69,"relative_atomic_mass":128.9331,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-130","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":130,"neutrons":70,"relative_atomic_mass":129.928506,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-131","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":131,"neutrons":71,"relative_atomic_mass":130.927248,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-132","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":132,"neutrons":72,"relative_atomic_mass":131.923321,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-133","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":133,"neutrons":73,"relative_atomic_mass":132.922348,"relative_atomic_mass_uncertainty":0.00005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-134","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":134,"neutrons":74,"relative_atomic_mass":133.91879,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-135","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":135,"neutrons":75,"relative_atomic_mass":134.918181,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-136","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":136,"neutrons":76,"relative_atomic_mass":135.914976,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-137","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":137,"neutrons":77,"relative_atomic_mass":136.914562,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-138","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":138,"neutrons":78,"relative_atomic_mass":137.91195,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-139","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":139,"neutrons":79,"relative_atomic_mass":138.911954,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-140","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":140,"neutrons":80,"relative_atomic_mass":139.90955,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-141","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":141,"neutrons":81,"relative_atomic_mass":140.9096147,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-142","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":142,"neutrons":82,"relative_atomic_mass":141.907729,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.27152,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-143","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":143,"neutrons":83,"relative_atomic_mass":142.90982,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.12174,"natural_abundance_uncertainty":0.00026,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-144","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":144,"neutrons":84,"relative_atomic_mass":143.910093,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.23798,"natural_abundance_uncertainty":0.00019,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-145","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":145,"neutrons":85,"relative_atomic_mass":144.9125793,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.08293,"natural_abundance_uncertainty":0.00012,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-146","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":146,"neutrons":86,"relative_atomic_mass":145.9131226,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.17189,"natural_abundance_uncertainty":0.00032,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-147","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":147,"neutrons":87,"relative_atomic_mass":146.9161061,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-148","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":148,"neutrons":88,"relative_atomic_mass":147.9168993,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":0.05756,"natural_abundance_uncertainty":0.00021,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-149","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":149,"neutrons":89,"relative_atomic_mass":148.9201548,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-150","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":150,"neutrons":90,"relative_atomic_mass":149.9209022,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.05638,"natural_abundance_uncertainty":0.00028,"naturally_occurring":true,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-151","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":151,"neutrons":91,"relative_atomic_mass":150.9238403,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-152","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":152,"neutrons":92,"relative_atomic_mass":151.924692,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-153","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":153,"neutrons":93,"relative_atomic_mass":152.927718,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-154","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":154,"neutrons":94,"relative_atomic_mass":153.92948,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-155","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":155,"neutrons":95,"relative_atomic_mass":154.9331357,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-156","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":156,"neutrons":96,"relative_atomic_mass":155.93508,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-157","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":157,"neutrons":97,"relative_atomic_mass":156.939386,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-158","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":158,"neutrons":98,"relative_atomic_mass":157.94197,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-159","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":159,"neutrons":99,"relative_atomic_mass":158.94653,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-160","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":160,"neutrons":100,"relative_atomic_mass":159.9494,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Nd-161","atomic_number":60,"element_symbol":"Nd","nist_symbol":"Nd","mass_number":161,"neutrons":101,"relative_atomic_mass":160.95428,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"144.242(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pm-126","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":126,"neutrons":65,"relative_atomic_mass":125.95792,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-127","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":127,"neutrons":66,"relative_atomic_mass":126.95192,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-128","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":128,"neutrons":67,"relative_atomic_mass":127.9487,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-129","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":129,"neutrons":68,"relative_atomic_mass":128.94323,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-130","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":130,"neutrons":69,"relative_atomic_mass":129.94053,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-131","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":131,"neutrons":70,"relative_atomic_mass":130.93567,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-132","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":132,"neutrons":71,"relative_atomic_mass":131.93384,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-133","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":133,"neutrons":72,"relative_atomic_mass":132.929782,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-134","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":134,"neutrons":73,"relative_atomic_mass":133.928353,"relative_atomic_mass_uncertainty":0.000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-135","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":135,"neutrons":74,"relative_atomic_mass":134.924823,"relative_atomic_mass_uncertainty":0.00007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-136","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":136,"neutrons":75,"relative_atomic_mass":135.923585,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-137","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":137,"neutrons":76,"relative_atomic_mass":136.92048,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-138","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":138,"neutrons":77,"relative_atomic_mass":137.919548,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-139","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":139,"neutrons":78,"relative_atomic_mass":138.9168,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-140","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":140,"neutrons":79,"relative_atomic_mass":139.91604,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-141","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":141,"neutrons":80,"relative_atomic_mass":140.913555,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-142","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":142,"neutrons":81,"relative_atomic_mass":141.91289,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-143","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":143,"neutrons":82,"relative_atomic_mass":142.9109383,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-144","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":144,"neutrons":83,"relative_atomic_mass":143.9125964,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-145","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":145,"neutrons":84,"relative_atomic_mass":144.9127559,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-146","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":146,"neutrons":85,"relative_atomic_mass":145.9147024,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-147","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":147,"neutrons":86,"relative_atomic_mass":146.915145,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-148","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":148,"neutrons":87,"relative_atomic_mass":147.9174819,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-149","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":149,"neutrons":88,"relative_atomic_mass":148.9183423,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-150","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":150,"neutrons":89,"relative_atomic_mass":149.920991,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-151","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":151,"neutrons":90,"relative_atomic_mass":150.9212175,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-152","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":152,"neutrons":91,"relative_atomic_mass":151.923506,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-153","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":153,"neutrons":92,"relative_atomic_mass":152.9241567,"relative_atomic_mass_uncertainty":0.0000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-154","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":154,"neutrons":93,"relative_atomic_mass":153.926472,"relative_atomic_mass_uncertainty":0.000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-155","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":155,"neutrons":94,"relative_atomic_mass":154.928137,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-156","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":156,"neutrons":95,"relative_atomic_mass":155.9311175,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-157","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":157,"neutrons":96,"relative_atomic_mass":156.9331214,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-158","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":158,"neutrons":97,"relative_atomic_mass":157.936565,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-159","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":159,"neutrons":98,"relative_atomic_mass":158.939287,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-160","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":160,"neutrons":99,"relative_atomic_mass":159.9431,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-161","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":161,"neutrons":100,"relative_atomic_mass":160.94607,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-162","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":162,"neutrons":101,"relative_atomic_mass":161.95022,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Pm-163","atomic_number":61,"element_symbol":"Pm","nist_symbol":"Pm","mass_number":163,"neutrons":102,"relative_atomic_mass":162.95357,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[145]","notes":null},{"isotope":"Sm-128","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":128,"neutrons":66,"relative_atomic_mass":127.95842,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-129","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":129,"neutrons":67,"relative_atomic_mass":128.95476,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-130","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":130,"neutrons":68,"relative_atomic_mass":129.949,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-131","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":131,"neutrons":69,"relative_atomic_mass":130.94618,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-132","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":132,"neutrons":70,"relative_atomic_mass":131.94087,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-133","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":133,"neutrons":71,"relative_atomic_mass":132.93856,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-134","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":134,"neutrons":72,"relative_atomic_mass":133.93411,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-135","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":135,"neutrons":73,"relative_atomic_mass":134.93252,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-136","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":136,"neutrons":74,"relative_atomic_mass":135.928276,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-137","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":137,"neutrons":75,"relative_atomic_mass":136.926971,"relative_atomic_mass_uncertainty":0.000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-138","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":138,"neutrons":76,"relative_atomic_mass":137.923244,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-139","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":139,"neutrons":77,"relative_atomic_mass":138.922297,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-140","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":140,"neutrons":78,"relative_atomic_mass":139.918995,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-141","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":141,"neutrons":79,"relative_atomic_mass":140.9184816,"relative_atomic_mass_uncertainty":0.0000092,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-142","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":142,"neutrons":80,"relative_atomic_mass":141.9152044,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-143","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":143,"neutrons":81,"relative_atomic_mass":142.9146353,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-144","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":144,"neutrons":82,"relative_atomic_mass":143.9120065,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":0.0307,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-145","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":145,"neutrons":83,"relative_atomic_mass":144.9134173,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-146","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":146,"neutrons":84,"relative_atomic_mass":145.913047,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-147","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":147,"neutrons":85,"relative_atomic_mass":146.9149044,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":0.1499,"natural_abundance_uncertainty":0.0018,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-148","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":148,"neutrons":86,"relative_atomic_mass":147.9148292,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":0.1124,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-149","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":149,"neutrons":87,"relative_atomic_mass":148.9171921,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.1382,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-150","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":150,"neutrons":88,"relative_atomic_mass":149.9172829,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.0738,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-151","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":151,"neutrons":89,"relative_atomic_mass":150.9199398,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-152","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":152,"neutrons":90,"relative_atomic_mass":151.9197397,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.2675,"natural_abundance_uncertainty":0.0016,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-153","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":153,"neutrons":91,"relative_atomic_mass":152.9221047,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-154","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":154,"neutrons":92,"relative_atomic_mass":153.9222169,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.2275,"natural_abundance_uncertainty":0.0029,"naturally_occurring":true,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-155","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":155,"neutrons":93,"relative_atomic_mass":154.9246477,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-156","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":156,"neutrons":94,"relative_atomic_mass":155.925536,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-157","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":157,"neutrons":95,"relative_atomic_mass":156.9284187,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-158","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":158,"neutrons":96,"relative_atomic_mass":157.929951,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-159","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":159,"neutrons":97,"relative_atomic_mass":158.9332172,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-160","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":160,"neutrons":98,"relative_atomic_mass":159.9353353,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-161","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":161,"neutrons":99,"relative_atomic_mass":160.9391602,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-162","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":162,"neutrons":100,"relative_atomic_mass":161.94146,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-163","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":163,"neutrons":101,"relative_atomic_mass":162.94555,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-164","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":164,"neutrons":102,"relative_atomic_mass":163.94836,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Sm-165","atomic_number":62,"element_symbol":"Sm","nist_symbol":"Sm","mass_number":165,"neutrons":103,"relative_atomic_mass":164.95297,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"150.36(2)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-130","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":130,"neutrons":67,"relative_atomic_mass":129.96369,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-131","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":131,"neutrons":68,"relative_atomic_mass":130.95784,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-132","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":132,"neutrons":69,"relative_atomic_mass":131.95467,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-133","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":133,"neutrons":70,"relative_atomic_mass":132.94929,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-134","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":134,"neutrons":71,"relative_atomic_mass":133.9464,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-135","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":135,"neutrons":72,"relative_atomic_mass":134.94187,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-136","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":136,"neutrons":73,"relative_atomic_mass":135.93962,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-137","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":137,"neutrons":74,"relative_atomic_mass":136.93546,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-138","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":138,"neutrons":75,"relative_atomic_mass":137.933709,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-139","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":139,"neutrons":76,"relative_atomic_mass":138.929792,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-140","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":140,"neutrons":77,"relative_atomic_mass":139.928088,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-141","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":141,"neutrons":78,"relative_atomic_mass":140.924932,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-142","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":142,"neutrons":79,"relative_atomic_mass":141.923442,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-143","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":143,"neutrons":80,"relative_atomic_mass":142.920299,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-144","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":144,"neutrons":81,"relative_atomic_mass":143.91882,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-145","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":145,"neutrons":82,"relative_atomic_mass":144.9162726,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-146","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":146,"neutrons":83,"relative_atomic_mass":145.917211,"relative_atomic_mass_uncertainty":0.0000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-147","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":147,"neutrons":84,"relative_atomic_mass":146.9167527,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-148","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":148,"neutrons":85,"relative_atomic_mass":147.918089,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-149","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":149,"neutrons":86,"relative_atomic_mass":148.9179378,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-150","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":150,"neutrons":87,"relative_atomic_mass":149.9197077,"relative_atomic_mass_uncertainty":0.0000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-151","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":151,"neutrons":88,"relative_atomic_mass":150.9198578,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.4781,"natural_abundance_uncertainty":0.0006,"naturally_occurring":true,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-152","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":152,"neutrons":89,"relative_atomic_mass":151.9217522,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-153","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":153,"neutrons":90,"relative_atomic_mass":152.921238,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.5219,"natural_abundance_uncertainty":0.0006,"naturally_occurring":true,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-154","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":154,"neutrons":91,"relative_atomic_mass":153.922987,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-155","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":155,"neutrons":92,"relative_atomic_mass":154.9229011,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-156","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":156,"neutrons":93,"relative_atomic_mass":155.9247605,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-157","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":157,"neutrons":94,"relative_atomic_mass":156.9254334,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-158","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":158,"neutrons":95,"relative_atomic_mass":157.927799,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-159","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":159,"neutrons":96,"relative_atomic_mass":158.9291001,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-160","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":160,"neutrons":97,"relative_atomic_mass":159.931851,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-161","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":161,"neutrons":98,"relative_atomic_mass":160.933664,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-162","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":162,"neutrons":99,"relative_atomic_mass":161.936989,"relative_atomic_mass_uncertainty":0.000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-163","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":163,"neutrons":100,"relative_atomic_mass":162.939196,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-164","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":164,"neutrons":101,"relative_atomic_mass":163.94274,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-165","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":165,"neutrons":102,"relative_atomic_mass":164.94559,"relative_atomic_mass_uncertainty":0.00035,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-166","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":166,"neutrons":103,"relative_atomic_mass":165.94962,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Eu-167","atomic_number":63,"element_symbol":"Eu","nist_symbol":"Eu","mass_number":167,"neutrons":104,"relative_atomic_mass":166.95289,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"151.964(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-133","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":133,"neutrons":69,"relative_atomic_mass":132.96133,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-134","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":134,"neutrons":70,"relative_atomic_mass":133.95566,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-135","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":135,"neutrons":71,"relative_atomic_mass":134.95245,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-136","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":136,"neutrons":72,"relative_atomic_mass":135.9473,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-137","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":137,"neutrons":73,"relative_atomic_mass":136.94502,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-138","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":138,"neutrons":74,"relative_atomic_mass":137.94025,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-139","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":139,"neutrons":75,"relative_atomic_mass":138.93813,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-140","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":140,"neutrons":76,"relative_atomic_mass":139.933674,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-141","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":141,"neutrons":77,"relative_atomic_mass":140.932126,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-142","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":142,"neutrons":78,"relative_atomic_mass":141.928116,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-143","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":143,"neutrons":79,"relative_atomic_mass":142.92675,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-144","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":144,"neutrons":80,"relative_atomic_mass":143.922963,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-145","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":145,"neutrons":81,"relative_atomic_mass":144.921713,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-146","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":146,"neutrons":82,"relative_atomic_mass":145.9183188,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-147","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":147,"neutrons":83,"relative_atomic_mass":146.9191014,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-148","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":148,"neutrons":84,"relative_atomic_mass":147.9181215,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-149","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":149,"neutrons":85,"relative_atomic_mass":148.9193481,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-150","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":150,"neutrons":86,"relative_atomic_mass":149.9186644,"relative_atomic_mass_uncertainty":0.0000066,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-151","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":151,"neutrons":87,"relative_atomic_mass":150.920356,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-152","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":152,"neutrons":88,"relative_atomic_mass":151.9197995,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.002,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-153","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":153,"neutrons":89,"relative_atomic_mass":152.921758,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-154","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":154,"neutrons":90,"relative_atomic_mass":153.9208741,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.0218,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-155","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":155,"neutrons":91,"relative_atomic_mass":154.9226305,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.148,"natural_abundance_uncertainty":0.0012,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-156","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":156,"neutrons":92,"relative_atomic_mass":155.9221312,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.2047,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-157","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":157,"neutrons":93,"relative_atomic_mass":156.9239686,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.1565,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-158","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":158,"neutrons":94,"relative_atomic_mass":157.9241123,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.2484,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-159","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":159,"neutrons":95,"relative_atomic_mass":158.926397,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-160","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":160,"neutrons":96,"relative_atomic_mass":159.9270624,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":0.2186,"natural_abundance_uncertainty":0.0019,"naturally_occurring":true,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-161","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":161,"neutrons":97,"relative_atomic_mass":160.9296775,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-162","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":162,"neutrons":98,"relative_atomic_mass":161.930993,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-163","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":163,"neutrons":99,"relative_atomic_mass":162.9341769,"relative_atomic_mass_uncertainty":0.000009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-164","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":164,"neutrons":100,"relative_atomic_mass":163.93583,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-165","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":165,"neutrons":101,"relative_atomic_mass":164.93936,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-166","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":166,"neutrons":102,"relative_atomic_mass":165.94146,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-167","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":167,"neutrons":103,"relative_atomic_mass":166.94545,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-168","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":168,"neutrons":104,"relative_atomic_mass":167.94808,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Gd-169","atomic_number":64,"element_symbol":"Gd","nist_symbol":"Gd","mass_number":169,"neutrons":105,"relative_atomic_mass":168.9526,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"157.25(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Tb-135","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":135,"neutrons":70,"relative_atomic_mass":134.96476,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-136","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":136,"neutrons":71,"relative_atomic_mass":135.96129,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-137","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":137,"neutrons":72,"relative_atomic_mass":136.95602,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-138","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":138,"neutrons":73,"relative_atomic_mass":137.95312,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-139","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":139,"neutrons":74,"relative_atomic_mass":138.94833,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-140","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":140,"neutrons":75,"relative_atomic_mass":139.94581,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-141","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":141,"neutrons":76,"relative_atomic_mass":140.94145,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-142","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":142,"neutrons":77,"relative_atomic_mass":141.93928,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-143","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":143,"neutrons":78,"relative_atomic_mass":142.935137,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-144","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":144,"neutrons":79,"relative_atomic_mass":143.933045,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-145","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":145,"neutrons":80,"relative_atomic_mass":144.92882,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-146","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":146,"neutrons":81,"relative_atomic_mass":145.927253,"relative_atomic_mass_uncertainty":0.000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-147","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":147,"neutrons":82,"relative_atomic_mass":146.9240548,"relative_atomic_mass_uncertainty":0.0000087,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-148","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":148,"neutrons":83,"relative_atomic_mass":147.924282,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-149","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":149,"neutrons":84,"relative_atomic_mass":148.9232535,"relative_atomic_mass_uncertainty":0.0000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-150","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":150,"neutrons":85,"relative_atomic_mass":149.9236649,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-151","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":151,"neutrons":86,"relative_atomic_mass":150.9231096,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-152","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":152,"neutrons":87,"relative_atomic_mass":151.924083,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-153","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":153,"neutrons":88,"relative_atomic_mass":152.9234424,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-154","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":154,"neutrons":89,"relative_atomic_mass":153.924685,"relative_atomic_mass_uncertainty":0.000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-155","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":155,"neutrons":90,"relative_atomic_mass":154.923511,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-156","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":156,"neutrons":91,"relative_atomic_mass":155.9247552,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-157","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":157,"neutrons":92,"relative_atomic_mass":156.924033,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-158","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":158,"neutrons":93,"relative_atomic_mass":157.9254209,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-159","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":159,"neutrons":94,"relative_atomic_mass":158.9253547,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-160","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":160,"neutrons":95,"relative_atomic_mass":159.9271756,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-161","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":161,"neutrons":96,"relative_atomic_mass":160.9275778,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-162","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":162,"neutrons":97,"relative_atomic_mass":161.929495,"relative_atomic_mass_uncertainty":0.000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-163","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":163,"neutrons":98,"relative_atomic_mass":162.9306547,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-164","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":164,"neutrons":99,"relative_atomic_mass":163.93336,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-165","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":165,"neutrons":100,"relative_atomic_mass":164.93498,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-166","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":166,"neutrons":101,"relative_atomic_mass":165.93786,"relative_atomic_mass_uncertainty":0.000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-167","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":167,"neutrons":102,"relative_atomic_mass":166.93996,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-168","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":168,"neutrons":103,"relative_atomic_mass":167.9434,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-169","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":169,"neutrons":104,"relative_atomic_mass":168.94597,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-170","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":170,"neutrons":105,"relative_atomic_mass":169.94984,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Tb-171","atomic_number":65,"element_symbol":"Tb","nist_symbol":"Tb","mass_number":171,"neutrons":106,"relative_atomic_mass":170.95273,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"158.92535(2)","notes":null},{"isotope":"Dy-138","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":138,"neutrons":72,"relative_atomic_mass":137.9625,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-139","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":139,"neutrons":73,"relative_atomic_mass":138.95959,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-140","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":140,"neutrons":74,"relative_atomic_mass":139.95402,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-141","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":141,"neutrons":75,"relative_atomic_mass":140.95128,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-142","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":142,"neutrons":76,"relative_atomic_mass":141.94619,"relative_atomic_mass_uncertainty":0.00078,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-143","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":143,"neutrons":77,"relative_atomic_mass":142.943994,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-144","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":144,"neutrons":78,"relative_atomic_mass":143.9392695,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-145","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":145,"neutrons":79,"relative_atomic_mass":144.937474,"relative_atomic_mass_uncertainty":0.000007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-146","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":146,"neutrons":80,"relative_atomic_mass":145.9328445,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-147","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":147,"neutrons":81,"relative_atomic_mass":146.9310827,"relative_atomic_mass_uncertainty":0.0000095,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-148","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":148,"neutrons":82,"relative_atomic_mass":147.927157,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-149","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":149,"neutrons":83,"relative_atomic_mass":148.927322,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-150","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":150,"neutrons":84,"relative_atomic_mass":149.9255933,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-151","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":151,"neutrons":85,"relative_atomic_mass":150.9261916,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-152","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":152,"neutrons":86,"relative_atomic_mass":151.9247253,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-153","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":153,"neutrons":87,"relative_atomic_mass":152.9257724,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-154","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":154,"neutrons":88,"relative_atomic_mass":153.9244293,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-155","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":155,"neutrons":89,"relative_atomic_mass":154.925759,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-156","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":156,"neutrons":90,"relative_atomic_mass":155.9242847,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.00056,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-157","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":157,"neutrons":91,"relative_atomic_mass":156.9254707,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-158","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":158,"neutrons":92,"relative_atomic_mass":157.9244159,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":0.00095,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-159","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":159,"neutrons":93,"relative_atomic_mass":158.925747,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-160","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":160,"neutrons":94,"relative_atomic_mass":159.9252046,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.02329,"natural_abundance_uncertainty":0.00018,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-161","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":161,"neutrons":95,"relative_atomic_mass":160.9269405,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.18889,"natural_abundance_uncertainty":0.00042,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-162","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":162,"neutrons":96,"relative_atomic_mass":161.9268056,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.25475,"natural_abundance_uncertainty":0.00036,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-163","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":163,"neutrons":97,"relative_atomic_mass":162.9287383,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.24896,"natural_abundance_uncertainty":0.00042,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-164","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":164,"neutrons":98,"relative_atomic_mass":163.9291819,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.2826,"natural_abundance_uncertainty":0.00054,"naturally_occurring":true,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-165","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":165,"neutrons":99,"relative_atomic_mass":164.9317105,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-166","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":166,"neutrons":100,"relative_atomic_mass":165.9328139,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-167","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":167,"neutrons":101,"relative_atomic_mass":166.935661,"relative_atomic_mass_uncertainty":0.000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-168","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":168,"neutrons":102,"relative_atomic_mass":167.93713,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-169","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":169,"neutrons":103,"relative_atomic_mass":168.94031,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-170","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":170,"neutrons":104,"relative_atomic_mass":169.94239,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-171","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":171,"neutrons":105,"relative_atomic_mass":170.94612,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-172","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":172,"neutrons":106,"relative_atomic_mass":171.94846,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Dy-173","atomic_number":66,"element_symbol":"Dy","nist_symbol":"Dy","mass_number":173,"neutrons":107,"relative_atomic_mass":172.95283,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"162.500(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ho-140","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":140,"neutrons":73,"relative_atomic_mass":139.96859,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-141","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":141,"neutrons":74,"relative_atomic_mass":140.96311,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-142","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":142,"neutrons":75,"relative_atomic_mass":141.96001,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-143","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":143,"neutrons":76,"relative_atomic_mass":142.95486,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-144","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":144,"neutrons":77,"relative_atomic_mass":143.9521097,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-145","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":145,"neutrons":78,"relative_atomic_mass":144.9472674,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-146","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":146,"neutrons":79,"relative_atomic_mass":145.9449935,"relative_atomic_mass_uncertainty":0.0000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-147","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":147,"neutrons":80,"relative_atomic_mass":146.9401423,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-148","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":148,"neutrons":81,"relative_atomic_mass":147.937744,"relative_atomic_mass_uncertainty":0.00009,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-149","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":149,"neutrons":82,"relative_atomic_mass":148.933803,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-150","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":150,"neutrons":83,"relative_atomic_mass":149.933498,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-151","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":151,"neutrons":84,"relative_atomic_mass":150.9316983,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-152","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":152,"neutrons":85,"relative_atomic_mass":151.931724,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-153","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":153,"neutrons":86,"relative_atomic_mass":152.9302064,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-154","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":154,"neutrons":87,"relative_atomic_mass":153.9306068,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-155","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":155,"neutrons":88,"relative_atomic_mass":154.929104,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-156","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":156,"neutrons":89,"relative_atomic_mass":155.929706,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-157","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":157,"neutrons":90,"relative_atomic_mass":156.928254,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-158","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":158,"neutrons":91,"relative_atomic_mass":157.928946,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-159","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":159,"neutrons":92,"relative_atomic_mass":158.9277197,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-160","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":160,"neutrons":93,"relative_atomic_mass":159.928737,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-161","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":161,"neutrons":94,"relative_atomic_mass":160.9278615,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-162","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":162,"neutrons":95,"relative_atomic_mass":161.9291023,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-163","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":163,"neutrons":96,"relative_atomic_mass":162.928741,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-164","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":164,"neutrons":97,"relative_atomic_mass":163.9302403,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-165","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":165,"neutrons":98,"relative_atomic_mass":164.9303288,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-166","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":166,"neutrons":99,"relative_atomic_mass":165.9322909,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-167","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":167,"neutrons":100,"relative_atomic_mass":166.9331385,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-168","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":168,"neutrons":101,"relative_atomic_mass":167.935522,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-169","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":169,"neutrons":102,"relative_atomic_mass":168.936878,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-170","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":170,"neutrons":103,"relative_atomic_mass":169.939625,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-171","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":171,"neutrons":104,"relative_atomic_mass":170.94147,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-172","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":172,"neutrons":105,"relative_atomic_mass":171.94473,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-173","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":173,"neutrons":106,"relative_atomic_mass":172.94702,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-174","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":174,"neutrons":107,"relative_atomic_mass":173.95095,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Ho-175","atomic_number":67,"element_symbol":"Ho","nist_symbol":"Ho","mass_number":175,"neutrons":108,"relative_atomic_mass":174.95362,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"164.93033(2)","notes":null},{"isotope":"Er-142","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":142,"neutrons":74,"relative_atomic_mass":141.9701,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-143","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":143,"neutrons":75,"relative_atomic_mass":142.96662,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-144","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":144,"neutrons":76,"relative_atomic_mass":143.9607,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-145","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":145,"neutrons":77,"relative_atomic_mass":144.95805,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-146","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":146,"neutrons":78,"relative_atomic_mass":145.9524184,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-147","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":147,"neutrons":79,"relative_atomic_mass":146.949964,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-148","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":148,"neutrons":80,"relative_atomic_mass":147.944735,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-149","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":149,"neutrons":81,"relative_atomic_mass":148.942306,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-150","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":150,"neutrons":82,"relative_atomic_mass":149.937916,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-151","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":151,"neutrons":83,"relative_atomic_mass":150.937449,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-152","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":152,"neutrons":84,"relative_atomic_mass":151.935057,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-153","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":153,"neutrons":85,"relative_atomic_mass":152.93508,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-154","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":154,"neutrons":86,"relative_atomic_mass":153.9327908,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-155","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":155,"neutrons":87,"relative_atomic_mass":154.9332159,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-156","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":156,"neutrons":88,"relative_atomic_mass":155.931067,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-157","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":157,"neutrons":89,"relative_atomic_mass":156.931949,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-158","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":158,"neutrons":90,"relative_atomic_mass":157.929893,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-159","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":159,"neutrons":91,"relative_atomic_mass":158.9306918,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-160","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":160,"neutrons":92,"relative_atomic_mass":159.929077,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-161","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":161,"neutrons":93,"relative_atomic_mass":160.9300046,"relative_atomic_mass_uncertainty":0.0000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-162","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":162,"neutrons":94,"relative_atomic_mass":161.9287884,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.00139,"natural_abundance_uncertainty":0.00005,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-163","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":163,"neutrons":95,"relative_atomic_mass":162.9300408,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-164","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":164,"neutrons":96,"relative_atomic_mass":163.9292088,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.01601,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-165","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":165,"neutrons":97,"relative_atomic_mass":164.9307345,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-166","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":166,"neutrons":98,"relative_atomic_mass":165.9302995,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.33503,"natural_abundance_uncertainty":0.00036,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-167","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":167,"neutrons":99,"relative_atomic_mass":166.9320546,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.22869,"natural_abundance_uncertainty":0.00009,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-168","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":168,"neutrons":100,"relative_atomic_mass":167.9323767,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.26978,"natural_abundance_uncertainty":0.00018,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-169","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":169,"neutrons":101,"relative_atomic_mass":168.9345968,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-170","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":170,"neutrons":102,"relative_atomic_mass":169.9354702,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":0.1491,"natural_abundance_uncertainty":0.00036,"naturally_occurring":true,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-171","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":171,"neutrons":103,"relative_atomic_mass":170.9380357,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-172","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":172,"neutrons":104,"relative_atomic_mass":171.9393619,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-173","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":173,"neutrons":105,"relative_atomic_mass":172.9424,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-174","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":174,"neutrons":106,"relative_atomic_mass":173.94423,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-175","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":175,"neutrons":107,"relative_atomic_mass":174.94777,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-176","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":176,"neutrons":108,"relative_atomic_mass":175.94994,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Er-177","atomic_number":68,"element_symbol":"Er","nist_symbol":"Er","mass_number":177,"neutrons":109,"relative_atomic_mass":176.95399,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"167.259(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Tm-144","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":144,"neutrons":75,"relative_atomic_mass":143.97628,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-145","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":145,"neutrons":76,"relative_atomic_mass":144.97039,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-146","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":146,"neutrons":77,"relative_atomic_mass":145.96684,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-147","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":147,"neutrons":78,"relative_atomic_mass":146.9613799,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-148","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":148,"neutrons":79,"relative_atomic_mass":147.958384,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-149","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":149,"neutrons":80,"relative_atomic_mass":148.95289,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-150","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":150,"neutrons":81,"relative_atomic_mass":149.95009,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-151","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":151,"neutrons":82,"relative_atomic_mass":150.945488,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-152","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":152,"neutrons":83,"relative_atomic_mass":151.944422,"relative_atomic_mass_uncertainty":0.000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-153","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":153,"neutrons":84,"relative_atomic_mass":152.94204,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-154","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":154,"neutrons":85,"relative_atomic_mass":153.94157,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-155","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":155,"neutrons":86,"relative_atomic_mass":154.93921,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-156","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":156,"neutrons":87,"relative_atomic_mass":155.938992,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-157","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":157,"neutrons":88,"relative_atomic_mass":156.936944,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-158","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":158,"neutrons":89,"relative_atomic_mass":157.93698,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-159","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":159,"neutrons":90,"relative_atomic_mass":158.934975,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-160","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":160,"neutrons":91,"relative_atomic_mass":159.935263,"relative_atomic_mass_uncertainty":0.000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-161","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":161,"neutrons":92,"relative_atomic_mass":160.933549,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-162","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":162,"neutrons":93,"relative_atomic_mass":161.934002,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-163","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":163,"neutrons":94,"relative_atomic_mass":162.9326592,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-164","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":164,"neutrons":95,"relative_atomic_mass":163.933544,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-165","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":165,"neutrons":96,"relative_atomic_mass":164.9324431,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-166","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":166,"neutrons":97,"relative_atomic_mass":165.933561,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-167","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":167,"neutrons":98,"relative_atomic_mass":166.9328562,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-168","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":168,"neutrons":99,"relative_atomic_mass":167.9341774,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-169","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":169,"neutrons":100,"relative_atomic_mass":168.9342179,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-170","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":170,"neutrons":101,"relative_atomic_mass":169.935806,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-171","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":171,"neutrons":102,"relative_atomic_mass":170.9364339,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-172","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":172,"neutrons":103,"relative_atomic_mass":171.9384055,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-173","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":173,"neutrons":104,"relative_atomic_mass":172.9396084,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-174","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":174,"neutrons":105,"relative_atomic_mass":173.942173,"relative_atomic_mass_uncertainty":0.000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-175","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":175,"neutrons":106,"relative_atomic_mass":174.943841,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-176","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":176,"neutrons":107,"relative_atomic_mass":175.947,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-177","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":177,"neutrons":108,"relative_atomic_mass":176.94904,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-178","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":178,"neutrons":109,"relative_atomic_mass":177.95264,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Tm-179","atomic_number":69,"element_symbol":"Tm","nist_symbol":"Tm","mass_number":179,"neutrons":110,"relative_atomic_mass":178.95534,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"168.93422(2)","notes":null},{"isotope":"Yb-148","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":148,"neutrons":78,"relative_atomic_mass":147.96758,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-149","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":149,"neutrons":79,"relative_atomic_mass":148.96436,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-150","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":150,"neutrons":80,"relative_atomic_mass":149.95852,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-151","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":151,"neutrons":81,"relative_atomic_mass":150.9554,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-152","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":152,"neutrons":82,"relative_atomic_mass":151.95027,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-153","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":153,"neutrons":83,"relative_atomic_mass":152.94932,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-154","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":154,"neutrons":84,"relative_atomic_mass":153.946396,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-155","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":155,"neutrons":85,"relative_atomic_mass":154.945783,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-156","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":156,"neutrons":86,"relative_atomic_mass":155.942825,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-157","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":157,"neutrons":87,"relative_atomic_mass":156.942645,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-158","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":158,"neutrons":88,"relative_atomic_mass":157.9398705,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-159","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":159,"neutrons":89,"relative_atomic_mass":158.940055,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-160","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":160,"neutrons":90,"relative_atomic_mass":159.937557,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-161","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":161,"neutrons":91,"relative_atomic_mass":160.937907,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-162","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":162,"neutrons":92,"relative_atomic_mass":161.935774,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-163","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":163,"neutrons":93,"relative_atomic_mass":162.93634,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-164","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":164,"neutrons":94,"relative_atomic_mass":163.934495,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-165","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":165,"neutrons":95,"relative_atomic_mass":164.93527,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-166","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":166,"neutrons":96,"relative_atomic_mass":165.9338747,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-167","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":167,"neutrons":97,"relative_atomic_mass":166.934953,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-168","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":168,"neutrons":98,"relative_atomic_mass":167.9338896,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.00123,"natural_abundance_uncertainty":0.00003,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-169","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":169,"neutrons":99,"relative_atomic_mass":168.9351825,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-170","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":170,"neutrons":100,"relative_atomic_mass":169.9347664,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.02982,"natural_abundance_uncertainty":0.00039,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-171","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":171,"neutrons":101,"relative_atomic_mass":170.9363302,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.1409,"natural_abundance_uncertainty":0.0014,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-172","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":172,"neutrons":102,"relative_atomic_mass":171.9363859,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.2168,"natural_abundance_uncertainty":0.0013,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-173","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":173,"neutrons":103,"relative_atomic_mass":172.9382151,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.16103,"natural_abundance_uncertainty":0.00063,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-174","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":174,"neutrons":104,"relative_atomic_mass":173.9388664,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.32026,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-175","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":175,"neutrons":105,"relative_atomic_mass":174.9412808,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-176","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":176,"neutrons":106,"relative_atomic_mass":175.9425764,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":0.12996,"natural_abundance_uncertainty":0.00083,"naturally_occurring":true,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-177","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":177,"neutrons":107,"relative_atomic_mass":176.9452656,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-178","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":178,"neutrons":108,"relative_atomic_mass":177.946651,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-179","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":179,"neutrons":109,"relative_atomic_mass":178.95004,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-180","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":180,"neutrons":110,"relative_atomic_mass":179.95212,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Yb-181","atomic_number":70,"element_symbol":"Yb","nist_symbol":"Yb","mass_number":181,"neutrons":111,"relative_atomic_mass":180.95589,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"173.054(5)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-150","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":150,"neutrons":79,"relative_atomic_mass":149.97355,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-151","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":151,"neutrons":80,"relative_atomic_mass":150.96768,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-152","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":152,"neutrons":81,"relative_atomic_mass":151.96412,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-153","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":153,"neutrons":82,"relative_atomic_mass":152.95875,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-154","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":154,"neutrons":83,"relative_atomic_mass":153.95736,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-155","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":155,"neutrons":84,"relative_atomic_mass":154.954321,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-156","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":156,"neutrons":85,"relative_atomic_mass":155.953033,"relative_atomic_mass_uncertainty":0.000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-157","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":157,"neutrons":86,"relative_atomic_mass":156.950127,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-158","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":158,"neutrons":87,"relative_atomic_mass":157.949316,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-159","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":159,"neutrons":88,"relative_atomic_mass":158.946636,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-160","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":160,"neutrons":89,"relative_atomic_mass":159.946033,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-161","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":161,"neutrons":90,"relative_atomic_mass":160.943572,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-162","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":162,"neutrons":91,"relative_atomic_mass":161.943283,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-163","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":163,"neutrons":92,"relative_atomic_mass":162.941179,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-164","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":164,"neutrons":93,"relative_atomic_mass":163.941339,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-165","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":165,"neutrons":94,"relative_atomic_mass":164.939407,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-166","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":166,"neutrons":95,"relative_atomic_mass":165.939859,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-167","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":167,"neutrons":96,"relative_atomic_mass":166.93827,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-168","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":168,"neutrons":97,"relative_atomic_mass":167.938736,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-169","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":169,"neutrons":98,"relative_atomic_mass":168.9376441,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-170","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":170,"neutrons":99,"relative_atomic_mass":169.938478,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-171","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":171,"neutrons":100,"relative_atomic_mass":170.937917,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-172","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":172,"neutrons":101,"relative_atomic_mass":171.9390891,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-173","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":173,"neutrons":102,"relative_atomic_mass":172.938934,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-174","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":174,"neutrons":103,"relative_atomic_mass":173.9403409,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-175","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":175,"neutrons":104,"relative_atomic_mass":174.9407752,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.97401,"natural_abundance_uncertainty":0.00013,"naturally_occurring":true,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-176","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":176,"neutrons":105,"relative_atomic_mass":175.9426897,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.02599,"natural_abundance_uncertainty":0.00013,"naturally_occurring":true,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-177","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":177,"neutrons":106,"relative_atomic_mass":176.9437615,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-178","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":178,"neutrons":107,"relative_atomic_mass":177.945958,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-179","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":179,"neutrons":108,"relative_atomic_mass":178.9473309,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-180","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":180,"neutrons":109,"relative_atomic_mass":179.949888,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-181","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":181,"neutrons":110,"relative_atomic_mass":180.95191,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-182","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":182,"neutrons":111,"relative_atomic_mass":181.95504,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-183","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":183,"neutrons":112,"relative_atomic_mass":182.957363,"relative_atomic_mass_uncertainty":0.000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-184","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":184,"neutrons":113,"relative_atomic_mass":183.96091,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Lu-185","atomic_number":71,"element_symbol":"Lu","nist_symbol":"Lu","mass_number":185,"neutrons":114,"relative_atomic_mass":184.96362,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"174.9668(1)","notes":"g: geologically exceptional specimens known"},{"isotope":"Hf-153","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":153,"neutrons":81,"relative_atomic_mass":152.97069,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-154","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":154,"neutrons":82,"relative_atomic_mass":153.96486,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-155","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":155,"neutrons":83,"relative_atomic_mass":154.96311,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-156","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":156,"neutrons":84,"relative_atomic_mass":155.95935,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-157","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":157,"neutrons":85,"relative_atomic_mass":156.95824,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-158","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":158,"neutrons":86,"relative_atomic_mass":157.954801,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-159","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":159,"neutrons":87,"relative_atomic_mass":158.953996,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-160","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":160,"neutrons":88,"relative_atomic_mass":159.950691,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-161","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":161,"neutrons":89,"relative_atomic_mass":160.950278,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-162","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":162,"neutrons":90,"relative_atomic_mass":161.9472148,"relative_atomic_mass_uncertainty":0.0000097,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-163","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":163,"neutrons":91,"relative_atomic_mass":162.947113,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-164","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":164,"neutrons":92,"relative_atomic_mass":163.944371,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-165","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":165,"neutrons":93,"relative_atomic_mass":164.944567,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-166","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":166,"neutrons":94,"relative_atomic_mass":165.94218,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-167","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":167,"neutrons":95,"relative_atomic_mass":166.9426,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-168","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":168,"neutrons":96,"relative_atomic_mass":167.940568,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-169","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":169,"neutrons":97,"relative_atomic_mass":168.941259,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-170","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":170,"neutrons":98,"relative_atomic_mass":169.939609,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-171","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":171,"neutrons":99,"relative_atomic_mass":170.940492,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-172","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":172,"neutrons":100,"relative_atomic_mass":171.93945,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-173","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":173,"neutrons":101,"relative_atomic_mass":172.940513,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-174","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":174,"neutrons":102,"relative_atomic_mass":173.9400461,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":0.0016,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-175","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":175,"neutrons":103,"relative_atomic_mass":174.9415092,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-176","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":176,"neutrons":104,"relative_atomic_mass":175.9414076,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":0.0526,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-177","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":177,"neutrons":105,"relative_atomic_mass":176.9432277,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.186,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-178","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":178,"neutrons":106,"relative_atomic_mass":177.9437058,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.2728,"natural_abundance_uncertainty":0.0007,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-179","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":179,"neutrons":107,"relative_atomic_mass":178.9458232,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.1362,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-180","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":180,"neutrons":108,"relative_atomic_mass":179.946557,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.3508,"natural_abundance_uncertainty":0.0016,"naturally_occurring":true,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-181","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":181,"neutrons":109,"relative_atomic_mass":180.9491083,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-182","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":182,"neutrons":110,"relative_atomic_mass":181.9505612,"relative_atomic_mass_uncertainty":0.0000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-183","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":183,"neutrons":111,"relative_atomic_mass":182.95353,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-184","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":184,"neutrons":112,"relative_atomic_mass":183.955446,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-185","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":185,"neutrons":113,"relative_atomic_mass":184.958862,"relative_atomic_mass_uncertainty":0.000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-186","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":186,"neutrons":114,"relative_atomic_mass":185.960897,"relative_atomic_mass_uncertainty":0.000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-187","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":187,"neutrons":115,"relative_atomic_mass":186.96477,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-188","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":188,"neutrons":116,"relative_atomic_mass":187.96685,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Hf-189","atomic_number":72,"element_symbol":"Hf","nist_symbol":"Hf","mass_number":189,"neutrons":117,"relative_atomic_mass":188.97084,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"178.49(2)","notes":null},{"isotope":"Ta-155","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":155,"neutrons":82,"relative_atomic_mass":154.97424,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-156","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":156,"neutrons":83,"relative_atomic_mass":155.97203,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-157","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":157,"neutrons":84,"relative_atomic_mass":156.96818,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-158","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":158,"neutrons":85,"relative_atomic_mass":157.96654,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-159","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":159,"neutrons":86,"relative_atomic_mass":158.963023,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-160","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":160,"neutrons":87,"relative_atomic_mass":159.961488,"relative_atomic_mass_uncertainty":0.000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-161","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":161,"neutrons":88,"relative_atomic_mass":160.958452,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-162","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":162,"neutrons":89,"relative_atomic_mass":161.957294,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-163","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":163,"neutrons":90,"relative_atomic_mass":162.954337,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-164","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":164,"neutrons":91,"relative_atomic_mass":163.953534,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-165","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":165,"neutrons":92,"relative_atomic_mass":164.950781,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-166","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":166,"neutrons":93,"relative_atomic_mass":165.950512,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-167","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":167,"neutrons":94,"relative_atomic_mass":166.948093,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-168","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":168,"neutrons":95,"relative_atomic_mass":167.948047,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-169","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":169,"neutrons":96,"relative_atomic_mass":168.946011,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-170","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":170,"neutrons":97,"relative_atomic_mass":169.946175,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-171","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":171,"neutrons":98,"relative_atomic_mass":170.944476,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-172","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":172,"neutrons":99,"relative_atomic_mass":171.944895,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-173","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":173,"neutrons":100,"relative_atomic_mass":172.94375,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-174","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":174,"neutrons":101,"relative_atomic_mass":173.944454,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-175","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":175,"neutrons":102,"relative_atomic_mass":174.943737,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-176","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":176,"neutrons":103,"relative_atomic_mass":175.944857,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-177","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":177,"neutrons":104,"relative_atomic_mass":176.9444795,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-178","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":178,"neutrons":105,"relative_atomic_mass":177.945678,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-179","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":179,"neutrons":106,"relative_atomic_mass":178.9459366,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-180","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":180,"neutrons":107,"relative_atomic_mass":179.9474648,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":0.0001201,"natural_abundance_uncertainty":0.0000032,"naturally_occurring":true,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-181","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":181,"neutrons":108,"relative_atomic_mass":180.9479958,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.9998799,"natural_abundance_uncertainty":0.0000032,"naturally_occurring":true,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-182","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":182,"neutrons":109,"relative_atomic_mass":181.9501519,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-183","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":183,"neutrons":110,"relative_atomic_mass":182.9513726,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-184","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":184,"neutrons":111,"relative_atomic_mass":183.954008,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-185","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":185,"neutrons":112,"relative_atomic_mass":184.955559,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-186","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":186,"neutrons":113,"relative_atomic_mass":185.958551,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-187","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":187,"neutrons":114,"relative_atomic_mass":186.960386,"relative_atomic_mass_uncertainty":0.000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-188","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":188,"neutrons":115,"relative_atomic_mass":187.963916,"relative_atomic_mass_uncertainty":0.000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-189","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":189,"neutrons":116,"relative_atomic_mass":188.96583,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-190","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":190,"neutrons":117,"relative_atomic_mass":189.96939,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-191","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":191,"neutrons":118,"relative_atomic_mass":190.97156,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"Ta-192","atomic_number":73,"element_symbol":"Ta","nist_symbol":"Ta","mass_number":192,"neutrons":119,"relative_atomic_mass":191.97514,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"180.94788(2)","notes":null},{"isotope":"W-157","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":157,"neutrons":83,"relative_atomic_mass":156.97884,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-158","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":158,"neutrons":84,"relative_atomic_mass":157.97456,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-159","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":159,"neutrons":85,"relative_atomic_mass":158.97264,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-160","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":160,"neutrons":86,"relative_atomic_mass":159.96846,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-161","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":161,"neutrons":87,"relative_atomic_mass":160.9672,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-162","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":162,"neutrons":88,"relative_atomic_mass":161.963499,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-163","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":163,"neutrons":89,"relative_atomic_mass":162.962524,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-164","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":164,"neutrons":90,"relative_atomic_mass":163.958961,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-165","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":165,"neutrons":91,"relative_atomic_mass":164.958281,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-166","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":166,"neutrons":92,"relative_atomic_mass":165.955031,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-167","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":167,"neutrons":93,"relative_atomic_mass":166.954805,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-168","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":168,"neutrons":94,"relative_atomic_mass":167.951806,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-169","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":169,"neutrons":95,"relative_atomic_mass":168.951779,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-170","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":170,"neutrons":96,"relative_atomic_mass":169.949232,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-171","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":171,"neutrons":97,"relative_atomic_mass":170.949451,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-172","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":172,"neutrons":98,"relative_atomic_mass":171.947292,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-173","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":173,"neutrons":99,"relative_atomic_mass":172.947689,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-174","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":174,"neutrons":100,"relative_atomic_mass":173.946079,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-175","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":175,"neutrons":101,"relative_atomic_mass":174.946717,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-176","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":176,"neutrons":102,"relative_atomic_mass":175.945634,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-177","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":177,"neutrons":103,"relative_atomic_mass":176.946643,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-178","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":178,"neutrons":104,"relative_atomic_mass":177.945883,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-179","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":179,"neutrons":105,"relative_atomic_mass":178.947077,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-180","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":180,"neutrons":106,"relative_atomic_mass":179.9467108,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.0012,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-181","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":181,"neutrons":107,"relative_atomic_mass":180.9481978,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-182","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":182,"neutrons":108,"relative_atomic_mass":181.94820394,"relative_atomic_mass_uncertainty":9.1e-7,"mass_estimated":false,"natural_abundance":0.265,"natural_abundance_uncertainty":0.0016,"naturally_occurring":true,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-183","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":183,"neutrons":109,"relative_atomic_mass":182.95022275,"relative_atomic_mass_uncertainty":9e-7,"mass_estimated":false,"natural_abundance":0.1431,"natural_abundance_uncertainty":0.0004,"naturally_occurring":true,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-184","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":184,"neutrons":110,"relative_atomic_mass":183.95093092,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":0.3064,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-185","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":185,"neutrons":111,"relative_atomic_mass":184.95341897,"relative_atomic_mass_uncertainty":9.9e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-186","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":186,"neutrons":112,"relative_atomic_mass":185.9543628,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.2843,"natural_abundance_uncertainty":0.0019,"naturally_occurring":true,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-187","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":187,"neutrons":113,"relative_atomic_mass":186.9571588,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-188","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":188,"neutrons":114,"relative_atomic_mass":187.9584862,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-189","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":189,"neutrons":115,"relative_atomic_mass":188.961763,"relative_atomic_mass_uncertainty":0.000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-190","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":190,"neutrons":116,"relative_atomic_mass":189.963091,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-191","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":191,"neutrons":117,"relative_atomic_mass":190.966531,"relative_atomic_mass_uncertainty":0.000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-192","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":192,"neutrons":118,"relative_atomic_mass":191.96817,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-193","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":193,"neutrons":119,"relative_atomic_mass":192.97178,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"W-194","atomic_number":74,"element_symbol":"W","nist_symbol":"W","mass_number":194,"neutrons":120,"relative_atomic_mass":193.97367,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"183.84(1)","notes":null},{"isotope":"Re-159","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":159,"neutrons":84,"relative_atomic_mass":158.98418,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-160","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":160,"neutrons":85,"relative_atomic_mass":159.98182,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-161","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":161,"neutrons":86,"relative_atomic_mass":160.97757,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-162","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":162,"neutrons":87,"relative_atomic_mass":161.97584,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-163","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":163,"neutrons":88,"relative_atomic_mass":162.97208,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-164","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":164,"neutrons":89,"relative_atomic_mass":163.970453,"relative_atomic_mass_uncertainty":0.000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-165","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":165,"neutrons":90,"relative_atomic_mass":164.967103,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-166","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":166,"neutrons":91,"relative_atomic_mass":165.965761,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-167","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":167,"neutrons":92,"relative_atomic_mass":166.962595,"relative_atomic_mass_uncertainty":0.000044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-168","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":168,"neutrons":93,"relative_atomic_mass":167.961573,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-169","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":169,"neutrons":94,"relative_atomic_mass":168.958766,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-170","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":170,"neutrons":95,"relative_atomic_mass":169.95822,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-171","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":171,"neutrons":96,"relative_atomic_mass":170.955716,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-172","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":172,"neutrons":97,"relative_atomic_mass":171.95542,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-173","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":173,"neutrons":98,"relative_atomic_mass":172.953243,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-174","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":174,"neutrons":99,"relative_atomic_mass":173.953115,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-175","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":175,"neutrons":100,"relative_atomic_mass":174.951381,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-176","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":176,"neutrons":101,"relative_atomic_mass":175.951623,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-177","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":177,"neutrons":102,"relative_atomic_mass":176.950328,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-178","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":178,"neutrons":103,"relative_atomic_mass":177.950989,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-179","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":179,"neutrons":104,"relative_atomic_mass":178.949989,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-180","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":180,"neutrons":105,"relative_atomic_mass":179.950792,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-181","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":181,"neutrons":106,"relative_atomic_mass":180.950058,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-182","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":182,"neutrons":107,"relative_atomic_mass":181.95121,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-183","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":183,"neutrons":108,"relative_atomic_mass":182.9508196,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-184","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":184,"neutrons":109,"relative_atomic_mass":183.9525228,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-185","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":185,"neutrons":110,"relative_atomic_mass":184.9529545,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.374,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-186","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":186,"neutrons":111,"relative_atomic_mass":185.9549856,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-187","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":187,"neutrons":112,"relative_atomic_mass":186.9557501,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.626,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-188","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":188,"neutrons":113,"relative_atomic_mass":187.9581115,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-189","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":189,"neutrons":114,"relative_atomic_mass":188.959226,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-190","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":190,"neutrons":115,"relative_atomic_mass":189.961744,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-191","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":191,"neutrons":116,"relative_atomic_mass":190.963122,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-192","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":192,"neutrons":117,"relative_atomic_mass":191.966088,"relative_atomic_mass_uncertainty":0.000082,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-193","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":193,"neutrons":118,"relative_atomic_mass":192.967541,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-194","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":194,"neutrons":119,"relative_atomic_mass":193.97076,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-195","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":195,"neutrons":120,"relative_atomic_mass":194.97254,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-196","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":196,"neutrons":121,"relative_atomic_mass":195.9758,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-197","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":197,"neutrons":122,"relative_atomic_mass":196.97799,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Re-198","atomic_number":75,"element_symbol":"Re","nist_symbol":"Re","mass_number":198,"neutrons":123,"relative_atomic_mass":197.9816,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"186.207(1)","notes":null},{"isotope":"Os-161","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":161,"neutrons":85,"relative_atomic_mass":160.98903,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-162","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":162,"neutrons":86,"relative_atomic_mass":161.98443,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-163","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":163,"neutrons":87,"relative_atomic_mass":162.98241,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-164","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":164,"neutrons":88,"relative_atomic_mass":163.97802,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-165","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":165,"neutrons":89,"relative_atomic_mass":164.9766,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-166","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":166,"neutrons":90,"relative_atomic_mass":165.972692,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-167","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":167,"neutrons":91,"relative_atomic_mass":166.971549,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-168","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":168,"neutrons":92,"relative_atomic_mass":167.967808,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-169","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":169,"neutrons":93,"relative_atomic_mass":168.967018,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-170","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":170,"neutrons":94,"relative_atomic_mass":169.963578,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-171","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":171,"neutrons":95,"relative_atomic_mass":170.963174,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-172","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":172,"neutrons":96,"relative_atomic_mass":171.960017,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-173","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":173,"neutrons":97,"relative_atomic_mass":172.959808,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-174","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":174,"neutrons":98,"relative_atomic_mass":173.957064,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-175","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":175,"neutrons":99,"relative_atomic_mass":174.956945,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-176","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":176,"neutrons":100,"relative_atomic_mass":175.954806,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-177","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":177,"neutrons":101,"relative_atomic_mass":176.954966,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-178","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":178,"neutrons":102,"relative_atomic_mass":177.953254,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-179","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":179,"neutrons":103,"relative_atomic_mass":178.953817,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-180","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":180,"neutrons":104,"relative_atomic_mass":179.952375,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-181","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":181,"neutrons":105,"relative_atomic_mass":180.953247,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-182","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":182,"neutrons":106,"relative_atomic_mass":181.95211,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-183","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":183,"neutrons":107,"relative_atomic_mass":182.953125,"relative_atomic_mass_uncertainty":0.000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-184","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":184,"neutrons":108,"relative_atomic_mass":183.9524885,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.0002,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-185","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":185,"neutrons":109,"relative_atomic_mass":184.9540417,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-186","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":186,"neutrons":110,"relative_atomic_mass":185.953835,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0159,"natural_abundance_uncertainty":0.0003,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-187","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":187,"neutrons":111,"relative_atomic_mass":186.9557474,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.0196,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-188","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":188,"neutrons":112,"relative_atomic_mass":187.9558352,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":0.1324,"natural_abundance_uncertainty":0.0008,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-189","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":189,"neutrons":113,"relative_atomic_mass":188.9581442,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.1615,"natural_abundance_uncertainty":0.0005,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-190","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":190,"neutrons":114,"relative_atomic_mass":189.9584437,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":0.2626,"natural_abundance_uncertainty":0.0002,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-191","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":191,"neutrons":115,"relative_atomic_mass":190.9609264,"relative_atomic_mass_uncertainty":0.0000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-192","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":192,"neutrons":116,"relative_atomic_mass":191.961477,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":0.4078,"natural_abundance_uncertainty":0.0019,"naturally_occurring":true,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-193","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":193,"neutrons":117,"relative_atomic_mass":192.9641479,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-194","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":194,"neutrons":118,"relative_atomic_mass":193.9651772,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-195","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":195,"neutrons":119,"relative_atomic_mass":194.968318,"relative_atomic_mass_uncertainty":0.000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-196","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":196,"neutrons":120,"relative_atomic_mass":195.969641,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-197","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":197,"neutrons":121,"relative_atomic_mass":196.97283,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-198","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":198,"neutrons":122,"relative_atomic_mass":197.97441,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-199","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":199,"neutrons":123,"relative_atomic_mass":198.97801,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-200","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":200,"neutrons":124,"relative_atomic_mass":199.97984,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-201","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":201,"neutrons":125,"relative_atomic_mass":200.98364,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Os-202","atomic_number":76,"element_symbol":"Os","nist_symbol":"Os","mass_number":202,"neutrons":126,"relative_atomic_mass":201.98595,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"190.23(3)","notes":"g: geologically exceptional specimens known"},{"isotope":"Ir-164","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":164,"neutrons":87,"relative_atomic_mass":163.99191,"relative_atomic_mass_uncertainty":0.00034,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-165","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":165,"neutrons":88,"relative_atomic_mass":164.9875,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-166","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":166,"neutrons":89,"relative_atomic_mass":165.98566,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-167","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":167,"neutrons":90,"relative_atomic_mass":166.981666,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-168","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":168,"neutrons":91,"relative_atomic_mass":167.979907,"relative_atomic_mass_uncertainty":0.00008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-169","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":169,"neutrons":92,"relative_atomic_mass":168.976298,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-170","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":170,"neutrons":93,"relative_atomic_mass":169.974922,"relative_atomic_mass_uncertainty":0.000095,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-171","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":171,"neutrons":94,"relative_atomic_mass":170.97164,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-172","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":172,"neutrons":95,"relative_atomic_mass":171.970607,"relative_atomic_mass_uncertainty":0.000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-173","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":173,"neutrons":96,"relative_atomic_mass":172.967506,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-174","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":174,"neutrons":97,"relative_atomic_mass":173.966861,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-175","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":175,"neutrons":98,"relative_atomic_mass":174.96415,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-176","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":176,"neutrons":99,"relative_atomic_mass":175.96365,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-177","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":177,"neutrons":100,"relative_atomic_mass":176.961301,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-178","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":178,"neutrons":101,"relative_atomic_mass":177.961082,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-179","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":179,"neutrons":102,"relative_atomic_mass":178.95912,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-180","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":180,"neutrons":103,"relative_atomic_mass":179.959229,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-181","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":181,"neutrons":104,"relative_atomic_mass":180.957625,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-182","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":182,"neutrons":105,"relative_atomic_mass":181.958076,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-183","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":183,"neutrons":106,"relative_atomic_mass":182.95684,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-184","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":184,"neutrons":107,"relative_atomic_mass":183.957476,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-185","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":185,"neutrons":108,"relative_atomic_mass":184.956698,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-186","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":186,"neutrons":109,"relative_atomic_mass":185.957944,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-187","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":187,"neutrons":110,"relative_atomic_mass":186.957542,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-188","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":188,"neutrons":111,"relative_atomic_mass":187.958828,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-189","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":189,"neutrons":112,"relative_atomic_mass":188.958715,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-190","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":190,"neutrons":113,"relative_atomic_mass":189.9605412,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-191","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":191,"neutrons":114,"relative_atomic_mass":190.9605893,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":0.373,"natural_abundance_uncertainty":0.002,"naturally_occurring":true,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-192","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":192,"neutrons":115,"relative_atomic_mass":191.9626002,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-193","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":193,"neutrons":116,"relative_atomic_mass":192.9629216,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":0.627,"natural_abundance_uncertainty":0.002,"naturally_occurring":true,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-194","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":194,"neutrons":117,"relative_atomic_mass":193.9650735,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-195","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":195,"neutrons":118,"relative_atomic_mass":194.9659747,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-196","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":196,"neutrons":119,"relative_atomic_mass":195.968397,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-197","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":197,"neutrons":120,"relative_atomic_mass":196.969655,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-198","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":198,"neutrons":121,"relative_atomic_mass":197.97228,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-199","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":199,"neutrons":122,"relative_atomic_mass":198.973805,"relative_atomic_mass_uncertainty":0.000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-200","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":200,"neutrons":123,"relative_atomic_mass":199.9768,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-201","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":201,"neutrons":124,"relative_atomic_mass":200.97864,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-202","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":202,"neutrons":125,"relative_atomic_mass":201.98199,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-203","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":203,"neutrons":126,"relative_atomic_mass":202.98423,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Ir-204","atomic_number":77,"element_symbol":"Ir","nist_symbol":"Ir","mass_number":204,"neutrons":127,"relative_atomic_mass":203.9896,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"192.217(3)","notes":null},{"isotope":"Pt-166","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":166,"neutrons":88,"relative_atomic_mass":165.99486,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-167","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":167,"neutrons":89,"relative_atomic_mass":166.99269,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-168","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":168,"neutrons":90,"relative_atomic_mass":167.98813,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-169","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":169,"neutrons":91,"relative_atomic_mass":168.98657,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-170","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":170,"neutrons":92,"relative_atomic_mass":169.982496,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-171","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":171,"neutrons":93,"relative_atomic_mass":170.981245,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-172","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":172,"neutrons":94,"relative_atomic_mass":171.977351,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-173","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":173,"neutrons":95,"relative_atomic_mass":172.976443,"relative_atomic_mass_uncertainty":0.00006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-174","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":174,"neutrons":96,"relative_atomic_mass":173.97282,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-175","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":175,"neutrons":97,"relative_atomic_mass":174.97241,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-176","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":176,"neutrons":98,"relative_atomic_mass":175.968938,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-177","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":177,"neutrons":99,"relative_atomic_mass":176.96847,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-178","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":178,"neutrons":100,"relative_atomic_mass":177.96565,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-179","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":179,"neutrons":101,"relative_atomic_mass":178.965359,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-180","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":180,"neutrons":102,"relative_atomic_mass":179.963032,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-181","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":181,"neutrons":103,"relative_atomic_mass":180.963098,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-182","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":182,"neutrons":104,"relative_atomic_mass":181.961172,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-183","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":183,"neutrons":105,"relative_atomic_mass":182.961597,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-184","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":184,"neutrons":106,"relative_atomic_mass":183.959915,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-185","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":185,"neutrons":107,"relative_atomic_mass":184.960614,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-186","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":186,"neutrons":108,"relative_atomic_mass":185.959351,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-187","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":187,"neutrons":109,"relative_atomic_mass":186.960617,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-188","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":188,"neutrons":110,"relative_atomic_mass":187.9593889,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-189","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":189,"neutrons":111,"relative_atomic_mass":188.960831,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-190","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":190,"neutrons":112,"relative_atomic_mass":189.9599297,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":0.00012,"natural_abundance_uncertainty":0.00002,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-191","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":191,"neutrons":113,"relative_atomic_mass":190.9616729,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-192","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":192,"neutrons":114,"relative_atomic_mass":191.9610387,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":0.00782,"natural_abundance_uncertainty":0.00024,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-193","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":193,"neutrons":115,"relative_atomic_mass":192.9629824,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-194","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":194,"neutrons":116,"relative_atomic_mass":193.9626809,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":0.3286,"natural_abundance_uncertainty":0.004,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-195","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":195,"neutrons":117,"relative_atomic_mass":194.9647917,"relative_atomic_mass_uncertainty":0.000001,"mass_estimated":false,"natural_abundance":0.3378,"natural_abundance_uncertainty":0.0024,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-196","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":196,"neutrons":118,"relative_atomic_mass":195.96495209,"relative_atomic_mass_uncertainty":9.9e-7,"mass_estimated":false,"natural_abundance":0.2521,"natural_abundance_uncertainty":0.0034,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-197","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":197,"neutrons":119,"relative_atomic_mass":196.96734069,"relative_atomic_mass_uncertainty":9.4e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-198","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":198,"neutrons":120,"relative_atomic_mass":197.9678949,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":0.07356,"natural_abundance_uncertainty":0.0013,"naturally_occurring":true,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-199","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":199,"neutrons":121,"relative_atomic_mass":198.9705952,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-200","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":200,"neutrons":122,"relative_atomic_mass":199.971443,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-201","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":201,"neutrons":123,"relative_atomic_mass":200.974513,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-202","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":202,"neutrons":124,"relative_atomic_mass":201.975639,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-203","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":203,"neutrons":125,"relative_atomic_mass":202.97893,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-204","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":204,"neutrons":126,"relative_atomic_mass":203.98076,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-205","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":205,"neutrons":127,"relative_atomic_mass":204.98608,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Pt-206","atomic_number":78,"element_symbol":"Pt","nist_symbol":"Pt","mass_number":206,"neutrons":128,"relative_atomic_mass":205.98966,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"195.084(9)","notes":null},{"isotope":"Au-169","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":169,"neutrons":90,"relative_atomic_mass":168.99808,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-170","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":170,"neutrons":91,"relative_atomic_mass":169.99597,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-171","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":171,"neutrons":92,"relative_atomic_mass":170.991876,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-172","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":172,"neutrons":93,"relative_atomic_mass":171.989942,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-173","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":173,"neutrons":94,"relative_atomic_mass":172.986241,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-174","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":174,"neutrons":95,"relative_atomic_mass":173.984717,"relative_atomic_mass_uncertainty":0.000095,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-175","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":175,"neutrons":96,"relative_atomic_mass":174.981304,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-176","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":176,"neutrons":97,"relative_atomic_mass":175.98025,"relative_atomic_mass_uncertainty":0.000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-177","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":177,"neutrons":98,"relative_atomic_mass":176.97687,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-178","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":178,"neutrons":99,"relative_atomic_mass":177.976032,"relative_atomic_mass_uncertainty":0.000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-179","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":179,"neutrons":100,"relative_atomic_mass":178.973174,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-180","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":180,"neutrons":101,"relative_atomic_mass":179.972523,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-181","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":181,"neutrons":102,"relative_atomic_mass":180.970079,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-182","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":182,"neutrons":103,"relative_atomic_mass":181.969618,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-183","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":183,"neutrons":104,"relative_atomic_mass":182.967591,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-184","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":184,"neutrons":105,"relative_atomic_mass":183.967452,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-185","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":185,"neutrons":106,"relative_atomic_mass":184.96579,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-186","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":186,"neutrons":107,"relative_atomic_mass":185.965953,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-187","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":187,"neutrons":108,"relative_atomic_mass":186.964543,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-188","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":188,"neutrons":109,"relative_atomic_mass":187.965349,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-189","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":189,"neutrons":110,"relative_atomic_mass":188.963948,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-190","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":190,"neutrons":111,"relative_atomic_mass":189.964698,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-191","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":191,"neutrons":112,"relative_atomic_mass":190.963702,"relative_atomic_mass_uncertainty":0.00004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-192","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":192,"neutrons":113,"relative_atomic_mass":191.964814,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-193","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":193,"neutrons":114,"relative_atomic_mass":192.9641373,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-194","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":194,"neutrons":115,"relative_atomic_mass":193.9654178,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-195","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":195,"neutrons":116,"relative_atomic_mass":194.9650352,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-196","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":196,"neutrons":117,"relative_atomic_mass":195.9665699,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-197","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":197,"neutrons":118,"relative_atomic_mass":196.96656879,"relative_atomic_mass_uncertainty":7.1e-7,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-198","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":198,"neutrons":119,"relative_atomic_mass":197.96824242,"relative_atomic_mass_uncertainty":7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-199","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":199,"neutrons":120,"relative_atomic_mass":198.96876528,"relative_atomic_mass_uncertainty":7e-7,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-200","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":200,"neutrons":121,"relative_atomic_mass":199.970756,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-201","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":201,"neutrons":122,"relative_atomic_mass":200.9716575,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-202","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":202,"neutrons":123,"relative_atomic_mass":201.973856,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-203","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":203,"neutrons":124,"relative_atomic_mass":202.9751544,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-204","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":204,"neutrons":125,"relative_atomic_mass":203.97783,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-205","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":205,"neutrons":126,"relative_atomic_mass":204.97985,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-206","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":206,"neutrons":127,"relative_atomic_mass":205.98474,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-207","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":207,"neutrons":128,"relative_atomic_mass":206.9884,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-208","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":208,"neutrons":129,"relative_atomic_mass":207.99345,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-209","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":209,"neutrons":130,"relative_atomic_mass":208.99735,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Au-210","atomic_number":79,"element_symbol":"Au","nist_symbol":"Au","mass_number":210,"neutrons":131,"relative_atomic_mass":210.0025,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"196.966569(5)","notes":null},{"isotope":"Hg-171","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":171,"neutrons":91,"relative_atomic_mass":171.00353,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-172","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":172,"neutrons":92,"relative_atomic_mass":171.99881,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-173","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":173,"neutrons":93,"relative_atomic_mass":172.99709,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-174","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":174,"neutrons":94,"relative_atomic_mass":173.992865,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-175","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":175,"neutrons":95,"relative_atomic_mass":174.991441,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-176","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":176,"neutrons":96,"relative_atomic_mass":175.987361,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-177","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":177,"neutrons":97,"relative_atomic_mass":176.986277,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-178","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":178,"neutrons":98,"relative_atomic_mass":177.982484,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-179","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":179,"neutrons":99,"relative_atomic_mass":178.981831,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-180","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":180,"neutrons":100,"relative_atomic_mass":179.97826,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-181","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":181,"neutrons":101,"relative_atomic_mass":180.977819,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-182","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":182,"neutrons":102,"relative_atomic_mass":181.974689,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-183","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":183,"neutrons":103,"relative_atomic_mass":182.9744448,"relative_atomic_mass_uncertainty":0.0000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-184","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":184,"neutrons":104,"relative_atomic_mass":183.971714,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-185","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":185,"neutrons":105,"relative_atomic_mass":184.971899,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-186","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":186,"neutrons":106,"relative_atomic_mass":185.969362,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-187","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":187,"neutrons":107,"relative_atomic_mass":186.969814,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-188","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":188,"neutrons":108,"relative_atomic_mass":187.967567,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-189","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":189,"neutrons":109,"relative_atomic_mass":188.968195,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-190","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":190,"neutrons":110,"relative_atomic_mass":189.966323,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-191","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":191,"neutrons":111,"relative_atomic_mass":190.967157,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-192","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":192,"neutrons":112,"relative_atomic_mass":191.965635,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-193","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":193,"neutrons":113,"relative_atomic_mass":192.966653,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-194","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":194,"neutrons":114,"relative_atomic_mass":193.9654491,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-195","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":195,"neutrons":115,"relative_atomic_mass":194.966721,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-196","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":196,"neutrons":116,"relative_atomic_mass":195.9658326,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":0.0015,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-197","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":197,"neutrons":117,"relative_atomic_mass":196.9672128,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-198","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":198,"neutrons":118,"relative_atomic_mass":197.9667686,"relative_atomic_mass_uncertainty":5.2e-7,"mass_estimated":false,"natural_abundance":0.0997,"natural_abundance_uncertainty":0.002,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-199","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":199,"neutrons":119,"relative_atomic_mass":198.96828064,"relative_atomic_mass_uncertainty":4.6e-7,"mass_estimated":false,"natural_abundance":0.1687,"natural_abundance_uncertainty":0.0022,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-200","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":200,"neutrons":120,"relative_atomic_mass":199.96832659,"relative_atomic_mass_uncertainty":4.7e-7,"mass_estimated":false,"natural_abundance":0.231,"natural_abundance_uncertainty":0.0019,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-201","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":201,"neutrons":121,"relative_atomic_mass":200.97030284,"relative_atomic_mass_uncertainty":6.9e-7,"mass_estimated":false,"natural_abundance":0.1318,"natural_abundance_uncertainty":0.0009,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-202","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":202,"neutrons":122,"relative_atomic_mass":201.9706434,"relative_atomic_mass_uncertainty":6.9e-7,"mass_estimated":false,"natural_abundance":0.2986,"natural_abundance_uncertainty":0.0026,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-203","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":203,"neutrons":123,"relative_atomic_mass":202.9728728,"relative_atomic_mass_uncertainty":0.0000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-204","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":204,"neutrons":124,"relative_atomic_mass":203.97349398,"relative_atomic_mass_uncertainty":5.3e-7,"mass_estimated":false,"natural_abundance":0.0687,"natural_abundance_uncertainty":0.0015,"naturally_occurring":true,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-205","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":205,"neutrons":125,"relative_atomic_mass":204.9760734,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-206","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":206,"neutrons":126,"relative_atomic_mass":205.977514,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-207","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":207,"neutrons":127,"relative_atomic_mass":206.9823,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-208","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":208,"neutrons":128,"relative_atomic_mass":207.985759,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-209","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":209,"neutrons":129,"relative_atomic_mass":208.99072,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-210","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":210,"neutrons":130,"relative_atomic_mass":209.99424,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-211","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":211,"neutrons":131,"relative_atomic_mass":210.99933,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-212","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":212,"neutrons":132,"relative_atomic_mass":212.00296,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-213","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":213,"neutrons":133,"relative_atomic_mass":213.00823,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-214","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":214,"neutrons":134,"relative_atomic_mass":214.012,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-215","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":215,"neutrons":135,"relative_atomic_mass":215.0174,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Hg-216","atomic_number":80,"element_symbol":"Hg","nist_symbol":"Hg","mass_number":216,"neutrons":136,"relative_atomic_mass":216.02132,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"200.592(3)","notes":null},{"isotope":"Tl-176","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":176,"neutrons":95,"relative_atomic_mass":176.000624,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-177","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":177,"neutrons":96,"relative_atomic_mass":176.996431,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-178","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":178,"neutrons":97,"relative_atomic_mass":177.99485,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-179","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":179,"neutrons":98,"relative_atomic_mass":178.991111,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-180","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":180,"neutrons":99,"relative_atomic_mass":179.990057,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-181","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":181,"neutrons":100,"relative_atomic_mass":180.98626,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-182","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":182,"neutrons":101,"relative_atomic_mass":181.985713,"relative_atomic_mass_uncertainty":0.000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-183","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":183,"neutrons":102,"relative_atomic_mass":182.982193,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-184","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":184,"neutrons":103,"relative_atomic_mass":183.981886,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-185","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":185,"neutrons":104,"relative_atomic_mass":184.978789,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-186","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":186,"neutrons":105,"relative_atomic_mass":185.978651,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-187","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":187,"neutrons":106,"relative_atomic_mass":186.9759063,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-188","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":188,"neutrons":107,"relative_atomic_mass":187.976021,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-189","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":189,"neutrons":108,"relative_atomic_mass":188.973588,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-190","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":190,"neutrons":109,"relative_atomic_mass":189.973828,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-191","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":191,"neutrons":110,"relative_atomic_mass":190.9717842,"relative_atomic_mass_uncertainty":0.0000079,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-192","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":192,"neutrons":111,"relative_atomic_mass":191.972225,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-193","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":193,"neutrons":112,"relative_atomic_mass":192.970502,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-194","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":194,"neutrons":113,"relative_atomic_mass":193.971081,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-195","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":195,"neutrons":114,"relative_atomic_mass":194.969774,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-196","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":196,"neutrons":115,"relative_atomic_mass":195.970481,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-197","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":197,"neutrons":116,"relative_atomic_mass":196.969576,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-198","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":198,"neutrons":117,"relative_atomic_mass":197.970483,"relative_atomic_mass_uncertainty":0.000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-199","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":199,"neutrons":118,"relative_atomic_mass":198.969877,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-200","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":200,"neutrons":119,"relative_atomic_mass":199.9709633,"relative_atomic_mass_uncertainty":0.0000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-201","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":201,"neutrons":120,"relative_atomic_mass":200.970822,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-202","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":202,"neutrons":121,"relative_atomic_mass":201.972102,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-203","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":203,"neutrons":122,"relative_atomic_mass":202.9723446,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.2952,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-204","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":204,"neutrons":123,"relative_atomic_mass":203.9738639,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-205","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":205,"neutrons":124,"relative_atomic_mass":204.9744278,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":0.7048,"natural_abundance_uncertainty":0.0001,"naturally_occurring":true,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-206","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":206,"neutrons":125,"relative_atomic_mass":205.9761106,"relative_atomic_mass_uncertainty":0.0000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-207","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":207,"neutrons":126,"relative_atomic_mass":206.9774197,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-208","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":208,"neutrons":127,"relative_atomic_mass":207.982019,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-209","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":209,"neutrons":128,"relative_atomic_mass":208.9853594,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-210","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":210,"neutrons":129,"relative_atomic_mass":209.990074,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-211","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":211,"neutrons":130,"relative_atomic_mass":210.993475,"relative_atomic_mass_uncertainty":0.000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-212","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":212,"neutrons":131,"relative_atomic_mass":211.99834,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-213","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":213,"neutrons":132,"relative_atomic_mass":213.001915,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-214","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":214,"neutrons":133,"relative_atomic_mass":214.00694,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-215","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":215,"neutrons":134,"relative_atomic_mass":215.01064,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-216","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":216,"neutrons":135,"relative_atomic_mass":216.0158,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-217","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":217,"neutrons":136,"relative_atomic_mass":217.01966,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Tl-218","atomic_number":81,"element_symbol":"Tl","nist_symbol":"Tl","mass_number":218,"neutrons":137,"relative_atomic_mass":218.02479,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[204.382,204.385]","notes":null},{"isotope":"Pb-178","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":178,"neutrons":96,"relative_atomic_mass":178.003831,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-179","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":179,"neutrons":97,"relative_atomic_mass":179.002201,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-180","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":180,"neutrons":98,"relative_atomic_mass":179.997928,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-181","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":181,"neutrons":99,"relative_atomic_mass":180.996653,"relative_atomic_mass_uncertainty":0.000081,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-182","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":182,"neutrons":100,"relative_atomic_mass":181.992672,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-183","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":183,"neutrons":101,"relative_atomic_mass":182.991872,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-184","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":184,"neutrons":102,"relative_atomic_mass":183.988136,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-185","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":185,"neutrons":103,"relative_atomic_mass":184.98761,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-186","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":186,"neutrons":104,"relative_atomic_mass":185.984238,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-187","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":187,"neutrons":105,"relative_atomic_mass":186.9839109,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-188","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":188,"neutrons":106,"relative_atomic_mass":187.980875,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-189","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":189,"neutrons":107,"relative_atomic_mass":188.980807,"relative_atomic_mass_uncertainty":0.000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-190","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":190,"neutrons":108,"relative_atomic_mass":189.978082,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-191","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":191,"neutrons":109,"relative_atomic_mass":190.978276,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-192","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":192,"neutrons":110,"relative_atomic_mass":191.975775,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-193","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":193,"neutrons":111,"relative_atomic_mass":192.976173,"relative_atomic_mass_uncertainty":0.000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-194","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":194,"neutrons":112,"relative_atomic_mass":193.974012,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-195","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":195,"neutrons":113,"relative_atomic_mass":194.974543,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-196","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":196,"neutrons":114,"relative_atomic_mass":195.972774,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-197","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":197,"neutrons":115,"relative_atomic_mass":196.9734312,"relative_atomic_mass_uncertainty":0.000006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-198","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":198,"neutrons":116,"relative_atomic_mass":197.972034,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-199","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":199,"neutrons":117,"relative_atomic_mass":198.972913,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-200","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":200,"neutrons":118,"relative_atomic_mass":199.971819,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-201","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":201,"neutrons":119,"relative_atomic_mass":200.972883,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-202","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":202,"neutrons":120,"relative_atomic_mass":201.972152,"relative_atomic_mass_uncertainty":0.000004,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-203","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":203,"neutrons":121,"relative_atomic_mass":202.9733911,"relative_atomic_mass_uncertainty":0.0000071,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-204","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":204,"neutrons":122,"relative_atomic_mass":203.973044,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.014,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-205","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":205,"neutrons":123,"relative_atomic_mass":204.9744822,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-206","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":206,"neutrons":124,"relative_atomic_mass":205.9744657,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.241,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-207","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":207,"neutrons":125,"relative_atomic_mass":206.9758973,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.221,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-208","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":208,"neutrons":126,"relative_atomic_mass":207.9766525,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":0.524,"natural_abundance_uncertainty":0.001,"naturally_occurring":true,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-209","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":209,"neutrons":127,"relative_atomic_mass":208.9810905,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-210","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":210,"neutrons":128,"relative_atomic_mass":209.9841889,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-211","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":211,"neutrons":129,"relative_atomic_mass":210.9887371,"relative_atomic_mass_uncertainty":0.0000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-212","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":212,"neutrons":130,"relative_atomic_mass":211.9918977,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-213","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":213,"neutrons":131,"relative_atomic_mass":212.9965629,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-214","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":214,"neutrons":132,"relative_atomic_mass":213.9998059,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-215","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":215,"neutrons":133,"relative_atomic_mass":215.00474,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-216","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":216,"neutrons":134,"relative_atomic_mass":216.00803,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-217","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":217,"neutrons":135,"relative_atomic_mass":217.01314,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-218","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":218,"neutrons":136,"relative_atomic_mass":218.01659,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-219","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":219,"neutrons":137,"relative_atomic_mass":219.02177,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Pb-220","atomic_number":82,"element_symbol":"Pb","nist_symbol":"Pb","mass_number":220,"neutrons":138,"relative_atomic_mass":220.02541,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"207.2(1)","notes":"g: geologically exceptional specimens known; r: range in isotopic composition limits precision"},{"isotope":"Bi-184","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":184,"neutrons":101,"relative_atomic_mass":184.001275,"relative_atomic_mass_uncertainty":0.000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-185","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":185,"neutrons":102,"relative_atomic_mass":184.9976,"relative_atomic_mass_uncertainty":0.000087,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-186","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":186,"neutrons":103,"relative_atomic_mass":185.996644,"relative_atomic_mass_uncertainty":0.000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-187","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":187,"neutrons":104,"relative_atomic_mass":186.993147,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-188","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":188,"neutrons":105,"relative_atomic_mass":187.992287,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-189","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":189,"neutrons":106,"relative_atomic_mass":188.989195,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-190","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":190,"neutrons":107,"relative_atomic_mass":189.988622,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-191","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":191,"neutrons":108,"relative_atomic_mass":190.9857866,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-192","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":192,"neutrons":109,"relative_atomic_mass":191.985469,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-193","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":193,"neutrons":110,"relative_atomic_mass":192.98296,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-194","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":194,"neutrons":111,"relative_atomic_mass":193.982785,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-195","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":195,"neutrons":112,"relative_atomic_mass":194.9806488,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-196","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":196,"neutrons":113,"relative_atomic_mass":195.980667,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-197","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":197,"neutrons":114,"relative_atomic_mass":196.9788651,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-198","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":198,"neutrons":115,"relative_atomic_mass":197.979206,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-199","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":199,"neutrons":116,"relative_atomic_mass":198.977673,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-200","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":200,"neutrons":117,"relative_atomic_mass":199.978131,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-201","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":201,"neutrons":118,"relative_atomic_mass":200.97701,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-202","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":202,"neutrons":119,"relative_atomic_mass":201.977734,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-203","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":203,"neutrons":120,"relative_atomic_mass":202.976893,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-204","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":204,"neutrons":121,"relative_atomic_mass":203.9778361,"relative_atomic_mass_uncertainty":0.0000099,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-205","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":205,"neutrons":122,"relative_atomic_mass":204.9773867,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-206","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":206,"neutrons":123,"relative_atomic_mass":205.9784993,"relative_atomic_mass_uncertainty":0.0000082,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-207","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":207,"neutrons":124,"relative_atomic_mass":206.978471,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-208","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":208,"neutrons":125,"relative_atomic_mass":207.9797425,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-209","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":209,"neutrons":126,"relative_atomic_mass":208.9803991,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-210","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":210,"neutrons":127,"relative_atomic_mass":209.9841207,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-211","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":211,"neutrons":128,"relative_atomic_mass":210.9872697,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-212","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":212,"neutrons":129,"relative_atomic_mass":211.991286,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-213","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":213,"neutrons":130,"relative_atomic_mass":212.9943851,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-214","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":214,"neutrons":131,"relative_atomic_mass":213.998712,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-215","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":215,"neutrons":132,"relative_atomic_mass":215.00177,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-216","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":216,"neutrons":133,"relative_atomic_mass":216.006306,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-217","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":217,"neutrons":134,"relative_atomic_mass":217.009372,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-218","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":218,"neutrons":135,"relative_atomic_mass":218.014188,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-219","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":219,"neutrons":136,"relative_atomic_mass":219.01748,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-220","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":220,"neutrons":137,"relative_atomic_mass":220.02235,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-221","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":221,"neutrons":138,"relative_atomic_mass":221.02587,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-222","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":222,"neutrons":139,"relative_atomic_mass":222.03078,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-223","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":223,"neutrons":140,"relative_atomic_mass":223.0345,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Bi-224","atomic_number":83,"element_symbol":"Bi","nist_symbol":"Bi","mass_number":224,"neutrons":141,"relative_atomic_mass":224.03947,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"208.98040(1)","notes":null},{"isotope":"Po-186","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":186,"neutrons":102,"relative_atomic_mass":186.004393,"relative_atomic_mass_uncertainty":0.000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-187","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":187,"neutrons":103,"relative_atomic_mass":187.003041,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-188","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":188,"neutrons":104,"relative_atomic_mass":187.999416,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-189","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":189,"neutrons":105,"relative_atomic_mass":188.998473,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-190","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":190,"neutrons":106,"relative_atomic_mass":189.995101,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-191","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":191,"neutrons":107,"relative_atomic_mass":190.9945585,"relative_atomic_mass_uncertainty":0.0000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-192","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":192,"neutrons":108,"relative_atomic_mass":191.991336,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-193","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":193,"neutrons":109,"relative_atomic_mass":192.991026,"relative_atomic_mass_uncertainty":0.000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-194","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":194,"neutrons":110,"relative_atomic_mass":193.988186,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-195","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":195,"neutrons":111,"relative_atomic_mass":194.988126,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-196","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":196,"neutrons":112,"relative_atomic_mass":195.985526,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-197","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":197,"neutrons":113,"relative_atomic_mass":196.98566,"relative_atomic_mass_uncertainty":0.000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-198","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":198,"neutrons":114,"relative_atomic_mass":197.983389,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-199","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":199,"neutrons":115,"relative_atomic_mass":198.983667,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-200","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":200,"neutrons":116,"relative_atomic_mass":199.981799,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-201","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":201,"neutrons":117,"relative_atomic_mass":200.9822598,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-202","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":202,"neutrons":118,"relative_atomic_mass":201.980758,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-203","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":203,"neutrons":119,"relative_atomic_mass":202.9814161,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-204","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":204,"neutrons":120,"relative_atomic_mass":203.98031,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-205","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":205,"neutrons":121,"relative_atomic_mass":204.981203,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-206","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":206,"neutrons":122,"relative_atomic_mass":205.980474,"relative_atomic_mass_uncertainty":0.0000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-207","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":207,"neutrons":123,"relative_atomic_mass":206.9815938,"relative_atomic_mass_uncertainty":0.0000072,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-208","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":208,"neutrons":124,"relative_atomic_mass":207.9812461,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-209","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":209,"neutrons":125,"relative_atomic_mass":208.9824308,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-210","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":210,"neutrons":126,"relative_atomic_mass":209.9828741,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-211","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":211,"neutrons":127,"relative_atomic_mass":210.9866536,"relative_atomic_mass_uncertainty":0.0000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-212","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":212,"neutrons":128,"relative_atomic_mass":211.9888684,"relative_atomic_mass_uncertainty":0.0000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-213","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":213,"neutrons":129,"relative_atomic_mass":212.9928576,"relative_atomic_mass_uncertainty":0.0000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-214","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":214,"neutrons":130,"relative_atomic_mass":213.9952017,"relative_atomic_mass_uncertainty":0.0000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-215","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":215,"neutrons":131,"relative_atomic_mass":214.9994201,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-216","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":216,"neutrons":132,"relative_atomic_mass":216.0019152,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-217","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":217,"neutrons":133,"relative_atomic_mass":217.0063182,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-218","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":218,"neutrons":134,"relative_atomic_mass":218.0089735,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-219","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":219,"neutrons":135,"relative_atomic_mass":219.013614,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-220","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":220,"neutrons":136,"relative_atomic_mass":220.016386,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-221","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":221,"neutrons":137,"relative_atomic_mass":221.021228,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-222","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":222,"neutrons":138,"relative_atomic_mass":222.02414,"relative_atomic_mass_uncertainty":0.000043,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-223","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":223,"neutrons":139,"relative_atomic_mass":223.02907,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-224","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":224,"neutrons":140,"relative_atomic_mass":224.03211,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-225","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":225,"neutrons":141,"relative_atomic_mass":225.03707,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-226","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":226,"neutrons":142,"relative_atomic_mass":226.04031,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"Po-227","atomic_number":84,"element_symbol":"Po","nist_symbol":"Po","mass_number":227,"neutrons":143,"relative_atomic_mass":227.04539,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[209]","notes":null},{"isotope":"At-191","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":191,"neutrons":106,"relative_atomic_mass":191.004148,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-192","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":192,"neutrons":107,"relative_atomic_mass":192.003152,"relative_atomic_mass_uncertainty":0.000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-193","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":193,"neutrons":108,"relative_atomic_mass":192.999927,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-194","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":194,"neutrons":109,"relative_atomic_mass":193.999236,"relative_atomic_mass_uncertainty":0.000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-195","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":195,"neutrons":110,"relative_atomic_mass":194.9962685,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-196","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":196,"neutrons":111,"relative_atomic_mass":195.9958,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-197","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":197,"neutrons":112,"relative_atomic_mass":196.993189,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-198","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":198,"neutrons":113,"relative_atomic_mass":197.992784,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-199","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":199,"neutrons":114,"relative_atomic_mass":198.9905277,"relative_atomic_mass_uncertainty":0.0000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-200","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":200,"neutrons":115,"relative_atomic_mass":199.990351,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-201","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":201,"neutrons":116,"relative_atomic_mass":200.9884171,"relative_atomic_mass_uncertainty":0.0000088,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-202","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":202,"neutrons":117,"relative_atomic_mass":201.98863,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-203","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":203,"neutrons":118,"relative_atomic_mass":202.986943,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-204","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":204,"neutrons":119,"relative_atomic_mass":203.987251,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-205","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":205,"neutrons":120,"relative_atomic_mass":204.986076,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-206","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":206,"neutrons":121,"relative_atomic_mass":205.986657,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-207","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":207,"neutrons":122,"relative_atomic_mass":206.9858,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-208","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":208,"neutrons":123,"relative_atomic_mass":207.9866133,"relative_atomic_mass_uncertainty":0.0000096,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-209","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":209,"neutrons":124,"relative_atomic_mass":208.9861702,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-210","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":210,"neutrons":125,"relative_atomic_mass":209.9871479,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-211","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":211,"neutrons":126,"relative_atomic_mass":210.9874966,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-212","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":212,"neutrons":127,"relative_atomic_mass":211.9907377,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-213","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":213,"neutrons":128,"relative_atomic_mass":212.992937,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-214","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":214,"neutrons":129,"relative_atomic_mass":213.9963721,"relative_atomic_mass_uncertainty":0.0000046,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-215","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":215,"neutrons":130,"relative_atomic_mass":214.9986528,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-216","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":216,"neutrons":131,"relative_atomic_mass":216.0024236,"relative_atomic_mass_uncertainty":0.0000039,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-217","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":217,"neutrons":132,"relative_atomic_mass":217.0047192,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-218","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":218,"neutrons":133,"relative_atomic_mass":218.008695,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-219","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":219,"neutrons":134,"relative_atomic_mass":219.0111618,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-220","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":220,"neutrons":135,"relative_atomic_mass":220.015433,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-221","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":221,"neutrons":136,"relative_atomic_mass":221.018017,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-222","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":222,"neutrons":137,"relative_atomic_mass":222.022494,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-223","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":223,"neutrons":138,"relative_atomic_mass":223.025151,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-224","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":224,"neutrons":139,"relative_atomic_mass":224.029749,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-225","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":225,"neutrons":140,"relative_atomic_mass":225.03263,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-226","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":226,"neutrons":141,"relative_atomic_mass":226.03716,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-227","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":227,"neutrons":142,"relative_atomic_mass":227.04024,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-228","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":228,"neutrons":143,"relative_atomic_mass":228.04475,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"At-229","atomic_number":85,"element_symbol":"At","nist_symbol":"At","mass_number":229,"neutrons":144,"relative_atomic_mass":229.04812,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[210]","notes":null},{"isotope":"Rn-193","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":193,"neutrons":107,"relative_atomic_mass":193.009708,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-194","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":194,"neutrons":108,"relative_atomic_mass":194.006144,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-195","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":195,"neutrons":109,"relative_atomic_mass":195.005422,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-196","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":196,"neutrons":110,"relative_atomic_mass":196.002116,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-197","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":197,"neutrons":111,"relative_atomic_mass":197.001585,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-198","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":198,"neutrons":112,"relative_atomic_mass":197.998679,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-199","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":199,"neutrons":113,"relative_atomic_mass":198.99839,"relative_atomic_mass_uncertainty":0.000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-200","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":200,"neutrons":114,"relative_atomic_mass":199.99569,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-201","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":201,"neutrons":115,"relative_atomic_mass":200.995628,"relative_atomic_mass_uncertainty":0.000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-202","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":202,"neutrons":116,"relative_atomic_mass":201.993264,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-203","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":203,"neutrons":117,"relative_atomic_mass":202.993388,"relative_atomic_mass_uncertainty":0.000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-204","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":204,"neutrons":118,"relative_atomic_mass":203.99143,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-205","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":205,"neutrons":119,"relative_atomic_mass":204.991719,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-206","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":206,"neutrons":120,"relative_atomic_mass":205.990214,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-207","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":207,"neutrons":121,"relative_atomic_mass":206.9907303,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-208","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":208,"neutrons":122,"relative_atomic_mass":207.989635,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-209","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":209,"neutrons":123,"relative_atomic_mass":208.990415,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-210","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":210,"neutrons":124,"relative_atomic_mass":209.9896891,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-211","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":211,"neutrons":125,"relative_atomic_mass":210.9906011,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-212","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":212,"neutrons":126,"relative_atomic_mass":211.9907039,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-213","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":213,"neutrons":127,"relative_atomic_mass":212.9938831,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-214","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":214,"neutrons":128,"relative_atomic_mass":213.995363,"relative_atomic_mass_uncertainty":0.0000099,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-215","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":215,"neutrons":129,"relative_atomic_mass":214.9987459,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-216","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":216,"neutrons":130,"relative_atomic_mass":216.0002719,"relative_atomic_mass_uncertainty":0.0000065,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-217","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":217,"neutrons":131,"relative_atomic_mass":217.003928,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-218","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":218,"neutrons":132,"relative_atomic_mass":218.0056016,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-219","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":219,"neutrons":133,"relative_atomic_mass":219.0094804,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-220","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":220,"neutrons":134,"relative_atomic_mass":220.0113941,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-221","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":221,"neutrons":135,"relative_atomic_mass":221.0155371,"relative_atomic_mass_uncertainty":0.0000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-222","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":222,"neutrons":136,"relative_atomic_mass":222.0175782,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-223","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":223,"neutrons":137,"relative_atomic_mass":223.0218893,"relative_atomic_mass_uncertainty":0.0000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-224","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":224,"neutrons":138,"relative_atomic_mass":224.024096,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-225","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":225,"neutrons":139,"relative_atomic_mass":225.028486,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-226","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":226,"neutrons":140,"relative_atomic_mass":226.030861,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-227","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":227,"neutrons":141,"relative_atomic_mass":227.035304,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-228","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":228,"neutrons":142,"relative_atomic_mass":228.037835,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-229","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":229,"neutrons":143,"relative_atomic_mass":229.042257,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-230","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":230,"neutrons":144,"relative_atomic_mass":230.04514,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Rn-231","atomic_number":86,"element_symbol":"Rn","nist_symbol":"Rn","mass_number":231,"neutrons":145,"relative_atomic_mass":231.04987,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[222]","notes":null},{"isotope":"Fr-199","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":199,"neutrons":112,"relative_atomic_mass":199.007259,"relative_atomic_mass_uncertainty":0.000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-200","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":200,"neutrons":113,"relative_atomic_mass":200.006586,"relative_atomic_mass_uncertainty":0.000063,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-201","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":201,"neutrons":114,"relative_atomic_mass":201.003867,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-202","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":202,"neutrons":115,"relative_atomic_mass":202.00332,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-203","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":203,"neutrons":116,"relative_atomic_mass":203.0009407,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-204","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":204,"neutrons":117,"relative_atomic_mass":204.000652,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-205","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":205,"neutrons":118,"relative_atomic_mass":204.9985939,"relative_atomic_mass_uncertainty":0.0000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-206","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":206,"neutrons":119,"relative_atomic_mass":205.998666,"relative_atomic_mass_uncertainty":0.00003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-207","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":207,"neutrons":120,"relative_atomic_mass":206.996946,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-208","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":208,"neutrons":121,"relative_atomic_mass":207.997138,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-209","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":209,"neutrons":122,"relative_atomic_mass":208.995955,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-210","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":210,"neutrons":123,"relative_atomic_mass":209.996422,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-211","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":211,"neutrons":124,"relative_atomic_mass":210.995556,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-212","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":212,"neutrons":125,"relative_atomic_mass":211.9962257,"relative_atomic_mass_uncertainty":0.0000094,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-213","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":213,"neutrons":126,"relative_atomic_mass":212.996186,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-214","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":214,"neutrons":127,"relative_atomic_mass":213.9989713,"relative_atomic_mass_uncertainty":0.0000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-215","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":215,"neutrons":128,"relative_atomic_mass":215.0003418,"relative_atomic_mass_uncertainty":0.0000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-216","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":216,"neutrons":129,"relative_atomic_mass":216.0031899,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-217","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":217,"neutrons":130,"relative_atomic_mass":217.0046323,"relative_atomic_mass_uncertainty":0.000007,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-218","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":218,"neutrons":131,"relative_atomic_mass":218.0075787,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-219","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":219,"neutrons":132,"relative_atomic_mass":219.0092524,"relative_atomic_mass_uncertainty":0.0000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-220","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":220,"neutrons":133,"relative_atomic_mass":220.0123277,"relative_atomic_mass_uncertainty":0.0000044,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-221","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":221,"neutrons":134,"relative_atomic_mass":221.0142552,"relative_atomic_mass_uncertainty":0.0000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-222","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":222,"neutrons":135,"relative_atomic_mass":222.017552,"relative_atomic_mass_uncertainty":0.000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-223","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":223,"neutrons":136,"relative_atomic_mass":223.019736,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-224","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":224,"neutrons":137,"relative_atomic_mass":224.023398,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-225","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":225,"neutrons":138,"relative_atomic_mass":225.025573,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-226","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":226,"neutrons":139,"relative_atomic_mass":226.029566,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-227","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":227,"neutrons":140,"relative_atomic_mass":227.031869,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-228","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":228,"neutrons":141,"relative_atomic_mass":228.035823,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-229","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":229,"neutrons":142,"relative_atomic_mass":229.038298,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-230","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":230,"neutrons":143,"relative_atomic_mass":230.042416,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-231","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":231,"neutrons":144,"relative_atomic_mass":231.045158,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-232","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":232,"neutrons":145,"relative_atomic_mass":232.04937,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Fr-233","atomic_number":87,"element_symbol":"Fr","nist_symbol":"Fr","mass_number":233,"neutrons":146,"relative_atomic_mass":233.05264,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[223]","notes":null},{"isotope":"Ra-201","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":201,"neutrons":113,"relative_atomic_mass":201.01271,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-202","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":202,"neutrons":114,"relative_atomic_mass":202.00976,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-203","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":203,"neutrons":115,"relative_atomic_mass":203.009304,"relative_atomic_mass_uncertainty":0.000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-204","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":204,"neutrons":116,"relative_atomic_mass":204.006492,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-205","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":205,"neutrons":117,"relative_atomic_mass":205.006268,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-206","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":206,"neutrons":118,"relative_atomic_mass":206.003828,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-207","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":207,"neutrons":119,"relative_atomic_mass":207.003799,"relative_atomic_mass_uncertainty":0.000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-208","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":208,"neutrons":120,"relative_atomic_mass":208.001841,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-209","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":209,"neutrons":121,"relative_atomic_mass":209.00199,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-210","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":210,"neutrons":122,"relative_atomic_mass":210.000494,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-211","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":211,"neutrons":123,"relative_atomic_mass":211.0008932,"relative_atomic_mass_uncertainty":0.0000085,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-212","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":212,"neutrons":124,"relative_atomic_mass":211.999787,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-213","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":213,"neutrons":125,"relative_atomic_mass":213.000384,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-214","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":214,"neutrons":126,"relative_atomic_mass":214.0000997,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-215","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":215,"neutrons":127,"relative_atomic_mass":215.0027204,"relative_atomic_mass_uncertainty":0.0000082,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-216","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":216,"neutrons":128,"relative_atomic_mass":216.0035334,"relative_atomic_mass_uncertainty":0.0000094,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-217","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":217,"neutrons":129,"relative_atomic_mass":217.0063207,"relative_atomic_mass_uncertainty":0.0000092,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-218","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":218,"neutrons":130,"relative_atomic_mass":218.007141,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-219","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":219,"neutrons":131,"relative_atomic_mass":219.0100855,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-220","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":220,"neutrons":132,"relative_atomic_mass":220.0110259,"relative_atomic_mass_uncertainty":0.0000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-221","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":221,"neutrons":133,"relative_atomic_mass":221.0139177,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-222","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":222,"neutrons":134,"relative_atomic_mass":222.0153748,"relative_atomic_mass_uncertainty":0.0000049,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-223","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":223,"neutrons":135,"relative_atomic_mass":223.0185023,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-224","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":224,"neutrons":136,"relative_atomic_mass":224.020212,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-225","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":225,"neutrons":137,"relative_atomic_mass":225.0236119,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-226","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":226,"neutrons":138,"relative_atomic_mass":226.0254103,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-227","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":227,"neutrons":139,"relative_atomic_mass":227.0291783,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-228","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":228,"neutrons":140,"relative_atomic_mass":228.0310707,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-229","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":229,"neutrons":141,"relative_atomic_mass":229.034942,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-230","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":230,"neutrons":142,"relative_atomic_mass":230.037055,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-231","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":231,"neutrons":143,"relative_atomic_mass":231.041027,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-232","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":232,"neutrons":144,"relative_atomic_mass":232.0434753,"relative_atomic_mass_uncertainty":0.0000098,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-233","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":233,"neutrons":145,"relative_atomic_mass":233.047582,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-234","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":234,"neutrons":146,"relative_atomic_mass":234.050342,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ra-235","atomic_number":88,"element_symbol":"Ra","nist_symbol":"Ra","mass_number":235,"neutrons":147,"relative_atomic_mass":235.05497,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[226]","notes":null},{"isotope":"Ac-206","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":206,"neutrons":117,"relative_atomic_mass":206.014452,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-207","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":207,"neutrons":118,"relative_atomic_mass":207.011966,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-208","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":208,"neutrons":119,"relative_atomic_mass":208.01155,"relative_atomic_mass_uncertainty":0.00006,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-209","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":209,"neutrons":120,"relative_atomic_mass":209.009495,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-210","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":210,"neutrons":121,"relative_atomic_mass":210.009436,"relative_atomic_mass_uncertainty":0.000062,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-211","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":211,"neutrons":122,"relative_atomic_mass":211.007732,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-212","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":212,"neutrons":123,"relative_atomic_mass":212.007813,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-213","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":213,"neutrons":124,"relative_atomic_mass":213.006609,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-214","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":214,"neutrons":125,"relative_atomic_mass":214.006918,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-215","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":215,"neutrons":126,"relative_atomic_mass":215.006475,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-216","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":216,"neutrons":127,"relative_atomic_mass":216.008743,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-217","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":217,"neutrons":128,"relative_atomic_mass":217.009344,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-218","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":218,"neutrons":129,"relative_atomic_mass":218.011642,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-219","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":219,"neutrons":130,"relative_atomic_mass":219.012421,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-220","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":220,"neutrons":131,"relative_atomic_mass":220.0147549,"relative_atomic_mass_uncertainty":0.0000066,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-221","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":221,"neutrons":132,"relative_atomic_mass":221.015592,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-222","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":222,"neutrons":133,"relative_atomic_mass":222.0178442,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-223","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":223,"neutrons":134,"relative_atomic_mass":223.0191377,"relative_atomic_mass_uncertainty":0.0000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-224","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":224,"neutrons":135,"relative_atomic_mass":224.0217232,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-225","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":225,"neutrons":136,"relative_atomic_mass":225.02323,"relative_atomic_mass_uncertainty":0.0000053,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-226","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":226,"neutrons":137,"relative_atomic_mass":226.0260984,"relative_atomic_mass_uncertainty":0.0000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-227","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":227,"neutrons":138,"relative_atomic_mass":227.0277523,"relative_atomic_mass_uncertainty":0.0000025,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-228","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":228,"neutrons":139,"relative_atomic_mass":228.0310215,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-229","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":229,"neutrons":140,"relative_atomic_mass":229.032956,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-230","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":230,"neutrons":141,"relative_atomic_mass":230.036327,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-231","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":231,"neutrons":142,"relative_atomic_mass":231.038393,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-232","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":232,"neutrons":143,"relative_atomic_mass":232.042034,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-233","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":233,"neutrons":144,"relative_atomic_mass":233.044346,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-234","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":234,"neutrons":145,"relative_atomic_mass":234.048139,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-235","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":235,"neutrons":146,"relative_atomic_mass":235.05084,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-236","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":236,"neutrons":147,"relative_atomic_mass":236.054988,"relative_atomic_mass_uncertainty":0.000041,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Ac-237","atomic_number":89,"element_symbol":"Ac","nist_symbol":"Ac","mass_number":237,"neutrons":148,"relative_atomic_mass":237.05827,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[227]","notes":null},{"isotope":"Th-208","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":208,"neutrons":118,"relative_atomic_mass":208.0179,"relative_atomic_mass_uncertainty":0.000036,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-209","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":209,"neutrons":119,"relative_atomic_mass":209.017753,"relative_atomic_mass_uncertainty":0.000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-210","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":210,"neutrons":120,"relative_atomic_mass":210.015094,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-211","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":211,"neutrons":121,"relative_atomic_mass":211.014929,"relative_atomic_mass_uncertainty":0.00008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-212","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":212,"neutrons":122,"relative_atomic_mass":212.012988,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-213","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":213,"neutrons":123,"relative_atomic_mass":213.013009,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-214","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":214,"neutrons":124,"relative_atomic_mass":214.0115,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-215","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":215,"neutrons":125,"relative_atomic_mass":215.0117248,"relative_atomic_mass_uncertainty":0.0000095,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-216","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":216,"neutrons":126,"relative_atomic_mass":216.011056,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-217","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":217,"neutrons":127,"relative_atomic_mass":217.013117,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-218","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":218,"neutrons":128,"relative_atomic_mass":218.013276,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-219","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":219,"neutrons":129,"relative_atomic_mass":219.015537,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-220","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":220,"neutrons":130,"relative_atomic_mass":220.015748,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-221","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":221,"neutrons":131,"relative_atomic_mass":221.018184,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-222","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":222,"neutrons":132,"relative_atomic_mass":222.018469,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-223","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":223,"neutrons":133,"relative_atomic_mass":223.0208119,"relative_atomic_mass_uncertainty":0.0000099,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-224","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":224,"neutrons":134,"relative_atomic_mass":224.021464,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-225","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":225,"neutrons":135,"relative_atomic_mass":225.0239514,"relative_atomic_mass_uncertainty":0.0000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-226","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":226,"neutrons":136,"relative_atomic_mass":226.0249034,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-227","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":227,"neutrons":137,"relative_atomic_mass":227.0277042,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-228","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":228,"neutrons":138,"relative_atomic_mass":228.0287413,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-229","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":229,"neutrons":139,"relative_atomic_mass":229.0317627,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-230","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":230,"neutrons":140,"relative_atomic_mass":230.0331341,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-231","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":231,"neutrons":141,"relative_atomic_mass":231.0363046,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-232","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":232,"neutrons":142,"relative_atomic_mass":232.0380558,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-233","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":233,"neutrons":143,"relative_atomic_mass":233.0415823,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-234","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":234,"neutrons":144,"relative_atomic_mass":234.0436014,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-235","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":235,"neutrons":145,"relative_atomic_mass":235.047255,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-236","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":236,"neutrons":146,"relative_atomic_mass":236.049657,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-237","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":237,"neutrons":147,"relative_atomic_mass":237.053629,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-238","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":238,"neutrons":148,"relative_atomic_mass":238.0565,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Th-239","atomic_number":90,"element_symbol":"Th","nist_symbol":"Th","mass_number":239,"neutrons":149,"relative_atomic_mass":239.06077,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"232.0377(4)","notes":"g: geologically exceptional specimens known"},{"isotope":"Pa-212","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":212,"neutrons":121,"relative_atomic_mass":212.023203,"relative_atomic_mass_uncertainty":0.00008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-213","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":213,"neutrons":122,"relative_atomic_mass":213.021109,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-214","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":214,"neutrons":123,"relative_atomic_mass":214.020918,"relative_atomic_mass_uncertainty":0.000082,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-215","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":215,"neutrons":124,"relative_atomic_mass":215.019183,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-216","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":216,"neutrons":125,"relative_atomic_mass":216.019109,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-217","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":217,"neutrons":126,"relative_atomic_mass":217.018325,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-218","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":218,"neutrons":127,"relative_atomic_mass":218.020059,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-219","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":219,"neutrons":128,"relative_atomic_mass":219.019904,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-220","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":220,"neutrons":129,"relative_atomic_mass":220.021705,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-221","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":221,"neutrons":130,"relative_atomic_mass":221.021875,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-222","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":222,"neutrons":131,"relative_atomic_mass":222.023784,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-223","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":223,"neutrons":132,"relative_atomic_mass":223.023963,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-224","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":224,"neutrons":133,"relative_atomic_mass":224.0256176,"relative_atomic_mass_uncertainty":0.0000082,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-225","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":225,"neutrons":134,"relative_atomic_mass":225.026131,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-226","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":226,"neutrons":135,"relative_atomic_mass":226.027948,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-227","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":227,"neutrons":136,"relative_atomic_mass":227.0288054,"relative_atomic_mass_uncertainty":0.000008,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-228","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":228,"neutrons":137,"relative_atomic_mass":228.0310517,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-229","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":229,"neutrons":138,"relative_atomic_mass":229.0320972,"relative_atomic_mass_uncertainty":0.0000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-230","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":230,"neutrons":139,"relative_atomic_mass":230.034541,"relative_atomic_mass_uncertainty":0.0000035,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-231","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":231,"neutrons":140,"relative_atomic_mass":231.0358842,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":1,"natural_abundance_uncertainty":null,"naturally_occurring":true,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-232","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":232,"neutrons":141,"relative_atomic_mass":232.0385917,"relative_atomic_mass_uncertainty":0.0000083,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-233","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":233,"neutrons":142,"relative_atomic_mass":233.0402472,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-234","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":234,"neutrons":143,"relative_atomic_mass":234.0433072,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-235","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":235,"neutrons":144,"relative_atomic_mass":235.045399,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-236","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":236,"neutrons":145,"relative_atomic_mass":236.048668,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-237","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":237,"neutrons":146,"relative_atomic_mass":237.051023,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-238","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":238,"neutrons":147,"relative_atomic_mass":238.054637,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-239","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":239,"neutrons":148,"relative_atomic_mass":239.05726,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-240","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":240,"neutrons":149,"relative_atomic_mass":240.06098,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"Pa-241","atomic_number":91,"element_symbol":"Pa","nist_symbol":"Pa","mass_number":241,"neutrons":150,"relative_atomic_mass":241.06408,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"231.03588(2)","notes":null},{"isotope":"U-217","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":217,"neutrons":125,"relative_atomic_mass":217.02466,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-218","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":218,"neutrons":126,"relative_atomic_mass":218.023523,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-219","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":219,"neutrons":127,"relative_atomic_mass":219.024999,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-220","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":220,"neutrons":128,"relative_atomic_mass":220.02462,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-221","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":221,"neutrons":129,"relative_atomic_mass":221.02628,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-222","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":222,"neutrons":130,"relative_atomic_mass":222.026,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-223","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":223,"neutrons":131,"relative_atomic_mass":223.027739,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-224","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":224,"neutrons":132,"relative_atomic_mass":224.027605,"relative_atomic_mass_uncertainty":0.000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-225","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":225,"neutrons":133,"relative_atomic_mass":225.029391,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-226","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":226,"neutrons":134,"relative_atomic_mass":226.029339,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-227","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":227,"neutrons":135,"relative_atomic_mass":227.031157,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-228","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":228,"neutrons":136,"relative_atomic_mass":228.031371,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-229","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":229,"neutrons":137,"relative_atomic_mass":229.0335063,"relative_atomic_mass_uncertainty":0.0000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-230","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":230,"neutrons":138,"relative_atomic_mass":230.0339401,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-231","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":231,"neutrons":139,"relative_atomic_mass":231.0362939,"relative_atomic_mass_uncertainty":0.0000032,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-232","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":232,"neutrons":140,"relative_atomic_mass":232.0371563,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-233","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":233,"neutrons":141,"relative_atomic_mass":233.0396355,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-234","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":234,"neutrons":142,"relative_atomic_mass":234.0409523,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":0.000054,"natural_abundance_uncertainty":0.000005,"naturally_occurring":true,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-235","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":235,"neutrons":143,"relative_atomic_mass":235.0439301,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":0.007204,"natural_abundance_uncertainty":0.000006,"naturally_occurring":true,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-236","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":236,"neutrons":144,"relative_atomic_mass":236.0455682,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-237","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":237,"neutrons":145,"relative_atomic_mass":237.0487304,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-238","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":238,"neutrons":146,"relative_atomic_mass":238.0507884,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":0.992742,"natural_abundance_uncertainty":0.00001,"naturally_occurring":true,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-239","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":239,"neutrons":147,"relative_atomic_mass":239.0542935,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-240","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":240,"neutrons":148,"relative_atomic_mass":240.0565934,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-241","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":241,"neutrons":149,"relative_atomic_mass":241.06033,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-242","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":242,"neutrons":150,"relative_atomic_mass":242.06293,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"U-243","atomic_number":92,"element_symbol":"U","nist_symbol":"U","mass_number":243,"neutrons":151,"relative_atomic_mass":243.06699,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"238.02891(3)","notes":"g: geologically exceptional specimens known; m: modified isotopic compositions in commercial material"},{"isotope":"Np-219","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":219,"neutrons":126,"relative_atomic_mass":219.03143,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-220","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":220,"neutrons":127,"relative_atomic_mass":220.03254,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-221","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":221,"neutrons":128,"relative_atomic_mass":221.03204,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-222","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":222,"neutrons":129,"relative_atomic_mass":222.0333,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-223","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":223,"neutrons":130,"relative_atomic_mass":223.03285,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-224","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":224,"neutrons":131,"relative_atomic_mass":224.03422,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-225","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":225,"neutrons":132,"relative_atomic_mass":225.033911,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-226","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":226,"neutrons":133,"relative_atomic_mass":226.035188,"relative_atomic_mass_uncertainty":0.000095,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-227","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":227,"neutrons":134,"relative_atomic_mass":227.034957,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-228","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":228,"neutrons":135,"relative_atomic_mass":228.036067,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-229","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":229,"neutrons":136,"relative_atomic_mass":229.036264,"relative_atomic_mass_uncertainty":0.000093,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-230","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":230,"neutrons":137,"relative_atomic_mass":230.037828,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-231","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":231,"neutrons":138,"relative_atomic_mass":231.038245,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-232","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":232,"neutrons":139,"relative_atomic_mass":232.04011,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-233","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":233,"neutrons":140,"relative_atomic_mass":233.040741,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-234","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":234,"neutrons":141,"relative_atomic_mass":234.0428953,"relative_atomic_mass_uncertainty":0.0000091,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-235","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":235,"neutrons":142,"relative_atomic_mass":235.0440635,"relative_atomic_mass_uncertainty":0.0000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-236","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":236,"neutrons":143,"relative_atomic_mass":236.04657,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-237","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":237,"neutrons":144,"relative_atomic_mass":237.0481736,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-238","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":238,"neutrons":145,"relative_atomic_mass":238.0509466,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-239","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":239,"neutrons":146,"relative_atomic_mass":239.0529392,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-240","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":240,"neutrons":147,"relative_atomic_mass":240.056165,"relative_atomic_mass_uncertainty":0.000018,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-241","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":241,"neutrons":148,"relative_atomic_mass":241.058253,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-242","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":242,"neutrons":149,"relative_atomic_mass":242.06164,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-243","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":243,"neutrons":150,"relative_atomic_mass":243.06428,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-244","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":244,"neutrons":151,"relative_atomic_mass":244.06785,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Np-245","atomic_number":93,"element_symbol":"Np","nist_symbol":"Np","mass_number":245,"neutrons":152,"relative_atomic_mass":245.0708,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[237]","notes":null},{"isotope":"Pu-228","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":228,"neutrons":134,"relative_atomic_mass":228.038732,"relative_atomic_mass_uncertainty":0.000033,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-229","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":229,"neutrons":135,"relative_atomic_mass":229.040144,"relative_atomic_mass_uncertainty":0.000055,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-230","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":230,"neutrons":136,"relative_atomic_mass":230.03965,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-231","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":231,"neutrons":137,"relative_atomic_mass":231.041102,"relative_atomic_mass_uncertainty":0.000028,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-232","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":232,"neutrons":138,"relative_atomic_mass":232.041185,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-233","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":233,"neutrons":139,"relative_atomic_mass":233.042998,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-234","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":234,"neutrons":140,"relative_atomic_mass":234.0433174,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-235","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":235,"neutrons":141,"relative_atomic_mass":235.045286,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-236","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":236,"neutrons":142,"relative_atomic_mass":236.0460581,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-237","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":237,"neutrons":143,"relative_atomic_mass":237.0484098,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-238","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":238,"neutrons":144,"relative_atomic_mass":238.0495601,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-239","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":239,"neutrons":145,"relative_atomic_mass":239.0521636,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-240","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":240,"neutrons":146,"relative_atomic_mass":240.0538138,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-241","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":241,"neutrons":147,"relative_atomic_mass":241.0568517,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-242","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":242,"neutrons":148,"relative_atomic_mass":242.0587428,"relative_atomic_mass_uncertainty":0.000002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-243","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":243,"neutrons":149,"relative_atomic_mass":243.0620036,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-244","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":244,"neutrons":150,"relative_atomic_mass":244.0642053,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-245","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":245,"neutrons":151,"relative_atomic_mass":245.067826,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-246","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":246,"neutrons":152,"relative_atomic_mass":246.070205,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Pu-247","atomic_number":94,"element_symbol":"Pu","nist_symbol":"Pu","mass_number":247,"neutrons":153,"relative_atomic_mass":247.07419,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":"[244]","notes":null},{"isotope":"Am-230","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":230,"neutrons":135,"relative_atomic_mass":230.04609,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-231","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":231,"neutrons":136,"relative_atomic_mass":231.04556,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-232","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":232,"neutrons":137,"relative_atomic_mass":232.04645,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-233","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":233,"neutrons":138,"relative_atomic_mass":233.04644,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-234","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":234,"neutrons":139,"relative_atomic_mass":234.04773,"relative_atomic_mass_uncertainty":0.00017,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-235","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":235,"neutrons":140,"relative_atomic_mass":235.047908,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-236","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":236,"neutrons":141,"relative_atomic_mass":236.04943,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-237","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":237,"neutrons":142,"relative_atomic_mass":237.049996,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-238","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":238,"neutrons":143,"relative_atomic_mass":238.051985,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-239","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":239,"neutrons":144,"relative_atomic_mass":239.0530247,"relative_atomic_mass_uncertainty":0.0000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-240","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":240,"neutrons":145,"relative_atomic_mass":240.0553,"relative_atomic_mass_uncertainty":0.000015,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-241","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":241,"neutrons":146,"relative_atomic_mass":241.0568293,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-242","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":242,"neutrons":147,"relative_atomic_mass":242.0595494,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-243","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":243,"neutrons":148,"relative_atomic_mass":243.0613813,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-244","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":244,"neutrons":149,"relative_atomic_mass":244.0642851,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-245","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":245,"neutrons":150,"relative_atomic_mass":245.0664548,"relative_atomic_mass_uncertainty":0.0000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-246","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":246,"neutrons":151,"relative_atomic_mass":246.069775,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-247","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":247,"neutrons":152,"relative_atomic_mass":247.07209,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-248","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":248,"neutrons":153,"relative_atomic_mass":248.07575,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Am-249","atomic_number":95,"element_symbol":"Am","nist_symbol":"Am","mass_number":249,"neutrons":154,"relative_atomic_mass":249.07848,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-232","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":232,"neutrons":136,"relative_atomic_mass":232.04982,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-233","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":233,"neutrons":137,"relative_atomic_mass":233.05077,"relative_atomic_mass_uncertainty":0.000077,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-234","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":234,"neutrons":138,"relative_atomic_mass":234.05016,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-235","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":235,"neutrons":139,"relative_atomic_mass":235.05154,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-236","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":236,"neutrons":140,"relative_atomic_mass":236.051374,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-237","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":237,"neutrons":141,"relative_atomic_mass":237.052869,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-238","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":238,"neutrons":142,"relative_atomic_mass":238.053081,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-239","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":239,"neutrons":143,"relative_atomic_mass":239.05491,"relative_atomic_mass_uncertainty":0.000058,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-240","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":240,"neutrons":144,"relative_atomic_mass":240.0555297,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-241","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":241,"neutrons":145,"relative_atomic_mass":241.0576532,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-242","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":242,"neutrons":146,"relative_atomic_mass":242.058836,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-243","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":243,"neutrons":147,"relative_atomic_mass":243.0613893,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-244","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":244,"neutrons":148,"relative_atomic_mass":244.0627528,"relative_atomic_mass_uncertainty":0.0000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-245","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":245,"neutrons":149,"relative_atomic_mass":245.0654915,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-246","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":246,"neutrons":150,"relative_atomic_mass":246.0672238,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-247","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":247,"neutrons":151,"relative_atomic_mass":247.0703541,"relative_atomic_mass_uncertainty":0.0000047,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-248","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":248,"neutrons":152,"relative_atomic_mass":248.0723499,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-249","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":249,"neutrons":153,"relative_atomic_mass":249.0759548,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-250","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":250,"neutrons":154,"relative_atomic_mass":250.078358,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-251","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":251,"neutrons":155,"relative_atomic_mass":251.082286,"relative_atomic_mass_uncertainty":0.000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cm-252","atomic_number":96,"element_symbol":"Cm","nist_symbol":"Cm","mass_number":252,"neutrons":156,"relative_atomic_mass":252.08487,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-234","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":234,"neutrons":137,"relative_atomic_mass":234.05727,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-235","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":235,"neutrons":138,"relative_atomic_mass":235.05658,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-236","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":236,"neutrons":139,"relative_atomic_mass":236.05748,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-237","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":237,"neutrons":140,"relative_atomic_mass":237.0571,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-238","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":238,"neutrons":141,"relative_atomic_mass":238.0582,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-239","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":239,"neutrons":142,"relative_atomic_mass":239.05824,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-240","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":240,"neutrons":143,"relative_atomic_mass":240.05976,"relative_atomic_mass_uncertainty":0.00016,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-241","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":241,"neutrons":144,"relative_atomic_mass":241.06016,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-242","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":242,"neutrons":145,"relative_atomic_mass":242.06198,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-243","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":243,"neutrons":146,"relative_atomic_mass":243.0630078,"relative_atomic_mass_uncertainty":0.0000051,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-244","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":244,"neutrons":147,"relative_atomic_mass":244.065181,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-245","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":245,"neutrons":148,"relative_atomic_mass":245.0663618,"relative_atomic_mass_uncertainty":0.0000024,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-246","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":246,"neutrons":149,"relative_atomic_mass":246.068673,"relative_atomic_mass_uncertainty":0.000064,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-247","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":247,"neutrons":150,"relative_atomic_mass":247.0703073,"relative_atomic_mass_uncertainty":0.0000059,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-248","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":248,"neutrons":151,"relative_atomic_mass":248.073088,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-249","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":249,"neutrons":152,"relative_atomic_mass":249.0749877,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-250","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":250,"neutrons":153,"relative_atomic_mass":250.0783167,"relative_atomic_mass_uncertainty":0.0000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-251","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":251,"neutrons":154,"relative_atomic_mass":251.080762,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-252","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":252,"neutrons":155,"relative_atomic_mass":252.08431,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-253","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":253,"neutrons":156,"relative_atomic_mass":253.08688,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bk-254","atomic_number":97,"element_symbol":"Bk","nist_symbol":"Bk","mass_number":254,"neutrons":157,"relative_atomic_mass":254.0906,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-237","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":237,"neutrons":139,"relative_atomic_mass":237.062198,"relative_atomic_mass_uncertainty":0.000094,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-238","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":238,"neutrons":140,"relative_atomic_mass":238.06149,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-239","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":239,"neutrons":141,"relative_atomic_mass":239.06253,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-240","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":240,"neutrons":142,"relative_atomic_mass":240.062256,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-241","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":241,"neutrons":143,"relative_atomic_mass":241.06369,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-242","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":242,"neutrons":144,"relative_atomic_mass":242.063754,"relative_atomic_mass_uncertainty":0.000014,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-243","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":243,"neutrons":145,"relative_atomic_mass":243.06548,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-244","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":244,"neutrons":146,"relative_atomic_mass":244.0660008,"relative_atomic_mass_uncertainty":0.0000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-245","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":245,"neutrons":147,"relative_atomic_mass":245.0680487,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-246","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":246,"neutrons":148,"relative_atomic_mass":246.0688055,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-247","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":247,"neutrons":149,"relative_atomic_mass":247.070965,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-248","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":248,"neutrons":150,"relative_atomic_mass":248.0721851,"relative_atomic_mass_uncertainty":0.0000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-249","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":249,"neutrons":151,"relative_atomic_mass":249.0748539,"relative_atomic_mass_uncertainty":0.0000023,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-250","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":250,"neutrons":152,"relative_atomic_mass":250.0764062,"relative_atomic_mass_uncertainty":0.0000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-251","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":251,"neutrons":153,"relative_atomic_mass":251.0795886,"relative_atomic_mass_uncertainty":0.0000048,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-252","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":252,"neutrons":154,"relative_atomic_mass":252.0816272,"relative_atomic_mass_uncertainty":0.0000056,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-253","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":253,"neutrons":155,"relative_atomic_mass":253.0851345,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-254","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":254,"neutrons":156,"relative_atomic_mass":254.087324,"relative_atomic_mass_uncertainty":0.000013,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-255","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":255,"neutrons":157,"relative_atomic_mass":255.09105,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cf-256","atomic_number":98,"element_symbol":"Cf","nist_symbol":"Cf","mass_number":256,"neutrons":158,"relative_atomic_mass":256.09344,"relative_atomic_mass_uncertainty":0.00034,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-239","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":239,"neutrons":140,"relative_atomic_mass":239.06823,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-240","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":240,"neutrons":141,"relative_atomic_mass":240.06892,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-241","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":241,"neutrons":142,"relative_atomic_mass":241.06856,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-242","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":242,"neutrons":143,"relative_atomic_mass":242.06957,"relative_atomic_mass_uncertainty":0.00028,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-243","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":243,"neutrons":144,"relative_atomic_mass":243.06951,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-244","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":244,"neutrons":145,"relative_atomic_mass":244.07088,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-245","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":245,"neutrons":146,"relative_atomic_mass":245.07125,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-246","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":246,"neutrons":147,"relative_atomic_mass":246.0729,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-247","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":247,"neutrons":148,"relative_atomic_mass":247.073622,"relative_atomic_mass_uncertainty":0.000021,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-248","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":248,"neutrons":149,"relative_atomic_mass":248.075471,"relative_atomic_mass_uncertainty":0.000056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-249","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":249,"neutrons":150,"relative_atomic_mass":249.076411,"relative_atomic_mass_uncertainty":0.000032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-250","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":250,"neutrons":151,"relative_atomic_mass":250.07861,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-251","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":251,"neutrons":152,"relative_atomic_mass":251.0799936,"relative_atomic_mass_uncertainty":0.0000067,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-252","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":252,"neutrons":153,"relative_atomic_mass":252.08298,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-253","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":253,"neutrons":154,"relative_atomic_mass":253.0848257,"relative_atomic_mass_uncertainty":0.0000027,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-254","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":254,"neutrons":155,"relative_atomic_mass":254.0880222,"relative_atomic_mass_uncertainty":0.0000045,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-255","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":255,"neutrons":156,"relative_atomic_mass":255.090275,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-256","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":256,"neutrons":157,"relative_atomic_mass":256.0936,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-257","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":257,"neutrons":158,"relative_atomic_mass":257.09598,"relative_atomic_mass_uncertainty":0.00044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Es-258","atomic_number":99,"element_symbol":"Es","nist_symbol":"Es","mass_number":258,"neutrons":159,"relative_atomic_mass":258.09952,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-241","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":241,"neutrons":141,"relative_atomic_mass":241.07421,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-242","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":242,"neutrons":142,"relative_atomic_mass":242.07343,"relative_atomic_mass_uncertainty":0.00043,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-243","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":243,"neutrons":143,"relative_atomic_mass":243.07446,"relative_atomic_mass_uncertainty":0.00023,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-244","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":244,"neutrons":144,"relative_atomic_mass":244.07404,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-245","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":245,"neutrons":145,"relative_atomic_mass":245.07535,"relative_atomic_mass_uncertainty":0.00021,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-246","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":246,"neutrons":146,"relative_atomic_mass":246.07535,"relative_atomic_mass_uncertainty":0.000017,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-247","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":247,"neutrons":147,"relative_atomic_mass":247.07694,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-248","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":248,"neutrons":148,"relative_atomic_mass":248.0771865,"relative_atomic_mass_uncertainty":0.0000092,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-249","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":249,"neutrons":149,"relative_atomic_mass":249.0789275,"relative_atomic_mass_uncertainty":0.0000068,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-250","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":250,"neutrons":150,"relative_atomic_mass":250.079521,"relative_atomic_mass_uncertainty":0.0000086,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-251","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":251,"neutrons":151,"relative_atomic_mass":251.08154,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-252","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":252,"neutrons":152,"relative_atomic_mass":252.0824671,"relative_atomic_mass_uncertainty":0.0000061,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-253","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":253,"neutrons":153,"relative_atomic_mass":253.0851846,"relative_atomic_mass_uncertainty":0.0000037,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-254","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":254,"neutrons":154,"relative_atomic_mass":254.0868544,"relative_atomic_mass_uncertainty":0.000003,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-255","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":255,"neutrons":155,"relative_atomic_mass":255.089964,"relative_atomic_mass_uncertainty":0.0000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-256","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":256,"neutrons":156,"relative_atomic_mass":256.0917745,"relative_atomic_mass_uncertainty":0.0000078,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-257","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":257,"neutrons":157,"relative_atomic_mass":257.0951061,"relative_atomic_mass_uncertainty":0.0000069,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-258","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":258,"neutrons":158,"relative_atomic_mass":258.09708,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-259","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":259,"neutrons":159,"relative_atomic_mass":259.1006,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fm-260","atomic_number":100,"element_symbol":"Fm","nist_symbol":"Fm","mass_number":260,"neutrons":160,"relative_atomic_mass":260.10281,"relative_atomic_mass_uncertainty":0.00055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-245","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":245,"neutrons":144,"relative_atomic_mass":245.08081,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-246","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":246,"neutrons":145,"relative_atomic_mass":246.08171,"relative_atomic_mass_uncertainty":0.00028,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-247","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":247,"neutrons":146,"relative_atomic_mass":247.08152,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-248","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":248,"neutrons":147,"relative_atomic_mass":248.08282,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-249","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":249,"neutrons":148,"relative_atomic_mass":249.08291,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-250","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":250,"neutrons":149,"relative_atomic_mass":250.08441,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-251","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":251,"neutrons":150,"relative_atomic_mass":251.084774,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-252","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":252,"neutrons":151,"relative_atomic_mass":252.08643,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-253","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":253,"neutrons":152,"relative_atomic_mass":253.087144,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-254","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":254,"neutrons":153,"relative_atomic_mass":254.08959,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-255","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":255,"neutrons":154,"relative_atomic_mass":255.0910841,"relative_atomic_mass_uncertainty":0.0000073,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-256","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":256,"neutrons":155,"relative_atomic_mass":256.09389,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-257","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":257,"neutrons":156,"relative_atomic_mass":257.0955424,"relative_atomic_mass_uncertainty":0.0000029,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-258","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":258,"neutrons":157,"relative_atomic_mass":258.0984315,"relative_atomic_mass_uncertainty":0.000005,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-259","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":259,"neutrons":158,"relative_atomic_mass":259.10051,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-260","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":260,"neutrons":159,"relative_atomic_mass":260.10365,"relative_atomic_mass_uncertainty":0.00034,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-261","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":261,"neutrons":160,"relative_atomic_mass":261.10583,"relative_atomic_mass_uncertainty":0.00062,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Md-262","atomic_number":101,"element_symbol":"Md","nist_symbol":"Md","mass_number":262,"neutrons":161,"relative_atomic_mass":262.1091,"relative_atomic_mass_uncertainty":0.00045,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-248","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":248,"neutrons":146,"relative_atomic_mass":248.08655,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-249","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":249,"neutrons":147,"relative_atomic_mass":249.0878,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-250","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":250,"neutrons":148,"relative_atomic_mass":250.08756,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-251","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":251,"neutrons":149,"relative_atomic_mass":251.08894,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-252","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":252,"neutrons":150,"relative_atomic_mass":252.088967,"relative_atomic_mass_uncertainty":0.00001,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-253","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":253,"neutrons":151,"relative_atomic_mass":253.0905641,"relative_atomic_mass_uncertainty":0.0000075,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-254","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":254,"neutrons":152,"relative_atomic_mass":254.090956,"relative_atomic_mass_uncertainty":0.000011,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-255","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":255,"neutrons":153,"relative_atomic_mass":255.093191,"relative_atomic_mass_uncertainty":0.000016,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-256","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":256,"neutrons":154,"relative_atomic_mass":256.0942829,"relative_atomic_mass_uncertainty":0.0000084,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-257","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":257,"neutrons":155,"relative_atomic_mass":257.0968878,"relative_atomic_mass_uncertainty":0.0000074,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-258","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":258,"neutrons":156,"relative_atomic_mass":258.09821,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-259","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":259,"neutrons":157,"relative_atomic_mass":259.10103,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-260","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":260,"neutrons":158,"relative_atomic_mass":260.10264,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-261","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":261,"neutrons":159,"relative_atomic_mass":261.1057,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-262","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":262,"neutrons":160,"relative_atomic_mass":262.10746,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-263","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":263,"neutrons":161,"relative_atomic_mass":263.11071,"relative_atomic_mass_uncertainty":0.00053,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"No-264","atomic_number":102,"element_symbol":"No","nist_symbol":"No","mass_number":264,"neutrons":162,"relative_atomic_mass":264.11273,"relative_atomic_mass_uncertainty":0.0007,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-251","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":251,"neutrons":148,"relative_atomic_mass":251.09418,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-252","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":252,"neutrons":149,"relative_atomic_mass":252.09526,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-253","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":253,"neutrons":150,"relative_atomic_mass":253.09509,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-254","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":254,"neutrons":151,"relative_atomic_mass":254.09648,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-255","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":255,"neutrons":152,"relative_atomic_mass":255.096562,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-256","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":256,"neutrons":153,"relative_atomic_mass":256.098494,"relative_atomic_mass_uncertainty":0.000089,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-257","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":257,"neutrons":154,"relative_atomic_mass":257.099418,"relative_atomic_mass_uncertainty":0.000047,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-258","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":258,"neutrons":155,"relative_atomic_mass":258.10176,"relative_atomic_mass_uncertainty":0.00011,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-259","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":259,"neutrons":156,"relative_atomic_mass":259.102902,"relative_atomic_mass_uncertainty":0.000076,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-260","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":260,"neutrons":157,"relative_atomic_mass":260.1055,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-261","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":261,"neutrons":158,"relative_atomic_mass":261.10688,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-262","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":262,"neutrons":159,"relative_atomic_mass":262.10961,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-263","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":263,"neutrons":160,"relative_atomic_mass":263.11136,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-264","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":264,"neutrons":161,"relative_atomic_mass":264.1142,"relative_atomic_mass_uncertainty":0.00047,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-265","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":265,"neutrons":162,"relative_atomic_mass":265.11619,"relative_atomic_mass_uncertainty":0.00065,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lr-266","atomic_number":103,"element_symbol":"Lr","nist_symbol":"Lr","mass_number":266,"neutrons":163,"relative_atomic_mass":266.11983,"relative_atomic_mass_uncertainty":0.00056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-253","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":253,"neutrons":149,"relative_atomic_mass":253.10044,"relative_atomic_mass_uncertainty":0.00044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-254","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":254,"neutrons":150,"relative_atomic_mass":254.10005,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-255","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":255,"neutrons":151,"relative_atomic_mass":255.10127,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-256","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":256,"neutrons":152,"relative_atomic_mass":256.101152,"relative_atomic_mass_uncertainty":0.000019,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-257","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":257,"neutrons":153,"relative_atomic_mass":257.102918,"relative_atomic_mass_uncertainty":0.000012,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-258","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":258,"neutrons":154,"relative_atomic_mass":258.103428,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-259","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":259,"neutrons":155,"relative_atomic_mass":259.105596,"relative_atomic_mass_uncertainty":0.000078,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-260","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":260,"neutrons":156,"relative_atomic_mass":260.10644,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-261","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":261,"neutrons":157,"relative_atomic_mass":261.108773,"relative_atomic_mass_uncertainty":0.000054,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-262","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":262,"neutrons":158,"relative_atomic_mass":262.10992,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-263","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":263,"neutrons":159,"relative_atomic_mass":263.11249,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-264","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":264,"neutrons":160,"relative_atomic_mass":264.11388,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-265","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":265,"neutrons":161,"relative_atomic_mass":265.11668,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-266","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":266,"neutrons":162,"relative_atomic_mass":266.11817,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-267","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":267,"neutrons":163,"relative_atomic_mass":267.12179,"relative_atomic_mass_uncertainty":0.00062,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rf-268","atomic_number":104,"element_symbol":"Rf","nist_symbol":"Rf","mass_number":268,"neutrons":164,"relative_atomic_mass":268.12397,"relative_atomic_mass_uncertainty":0.00077,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-255","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":255,"neutrons":150,"relative_atomic_mass":255.10707,"relative_atomic_mass_uncertainty":0.00045,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-256","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":256,"neutrons":151,"relative_atomic_mass":256.10789,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-257","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":257,"neutrons":152,"relative_atomic_mass":257.10758,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-258","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":258,"neutrons":153,"relative_atomic_mass":258.10928,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-259","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":259,"neutrons":154,"relative_atomic_mass":259.109492,"relative_atomic_mass_uncertainty":0.000057,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-260","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":260,"neutrons":155,"relative_atomic_mass":260.1113,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-261","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":261,"neutrons":156,"relative_atomic_mass":261.11192,"relative_atomic_mass_uncertainty":0.00012,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-262","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":262,"neutrons":157,"relative_atomic_mass":262.11407,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-263","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":263,"neutrons":158,"relative_atomic_mass":263.11499,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-264","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":264,"neutrons":159,"relative_atomic_mass":264.11741,"relative_atomic_mass_uncertainty":0.00025,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-265","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":265,"neutrons":160,"relative_atomic_mass":265.11861,"relative_atomic_mass_uncertainty":0.00024,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-266","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":266,"neutrons":161,"relative_atomic_mass":266.12103,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-267","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":267,"neutrons":162,"relative_atomic_mass":267.12247,"relative_atomic_mass_uncertainty":0.00044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-268","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":268,"neutrons":163,"relative_atomic_mass":268.12567,"relative_atomic_mass_uncertainty":0.00057,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-269","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":269,"neutrons":164,"relative_atomic_mass":269.12791,"relative_atomic_mass_uncertainty":0.00073,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Db-270","atomic_number":105,"element_symbol":"Db","nist_symbol":"Db","mass_number":270,"neutrons":165,"relative_atomic_mass":270.13136,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-258","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":258,"neutrons":152,"relative_atomic_mass":258.11298,"relative_atomic_mass_uncertainty":0.00044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-259","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":259,"neutrons":153,"relative_atomic_mass":259.1144,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-260","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":260,"neutrons":154,"relative_atomic_mass":260.114384,"relative_atomic_mass_uncertainty":0.000022,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-261","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":261,"neutrons":155,"relative_atomic_mass":261.115949,"relative_atomic_mass_uncertainty":0.00002,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-262","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":262,"neutrons":156,"relative_atomic_mass":262.116337,"relative_atomic_mass_uncertainty":0.000038,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-263","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":263,"neutrons":157,"relative_atomic_mass":263.11829,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-264","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":264,"neutrons":158,"relative_atomic_mass":264.11893,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-265","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":265,"neutrons":159,"relative_atomic_mass":265.12109,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-266","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":266,"neutrons":160,"relative_atomic_mass":266.12198,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-267","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":267,"neutrons":161,"relative_atomic_mass":267.12436,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-268","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":268,"neutrons":162,"relative_atomic_mass":268.12539,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-269","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":269,"neutrons":163,"relative_atomic_mass":269.12863,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-270","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":270,"neutrons":164,"relative_atomic_mass":270.13043,"relative_atomic_mass_uncertainty":0.0006,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-271","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":271,"neutrons":165,"relative_atomic_mass":271.13393,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-272","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":272,"neutrons":166,"relative_atomic_mass":272.13589,"relative_atomic_mass_uncertainty":0.00083,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Sg-273","atomic_number":106,"element_symbol":"Sg","nist_symbol":"Sg","mass_number":273,"neutrons":167,"relative_atomic_mass":273.13958,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-260","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":260,"neutrons":153,"relative_atomic_mass":260.12166,"relative_atomic_mass_uncertainty":0.00026,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-261","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":261,"neutrons":154,"relative_atomic_mass":261.12145,"relative_atomic_mass_uncertainty":0.00022,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-262","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":262,"neutrons":155,"relative_atomic_mass":262.12297,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-263","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":263,"neutrons":156,"relative_atomic_mass":263.12292,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-264","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":264,"neutrons":157,"relative_atomic_mass":264.12459,"relative_atomic_mass_uncertainty":0.00019,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-265","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":265,"neutrons":158,"relative_atomic_mass":265.12491,"relative_atomic_mass_uncertainty":0.00025,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-266","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":266,"neutrons":159,"relative_atomic_mass":266.12679,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-267","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":267,"neutrons":160,"relative_atomic_mass":267.1275,"relative_atomic_mass_uncertainty":0.00028,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-268","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":268,"neutrons":161,"relative_atomic_mass":268.12969,"relative_atomic_mass_uncertainty":0.00041,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-269","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":269,"neutrons":162,"relative_atomic_mass":269.13042,"relative_atomic_mass_uncertainty":0.0004,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-270","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":270,"neutrons":163,"relative_atomic_mass":270.13336,"relative_atomic_mass_uncertainty":0.00031,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-271","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":271,"neutrons":164,"relative_atomic_mass":271.13526,"relative_atomic_mass_uncertainty":0.00048,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-272","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":272,"neutrons":165,"relative_atomic_mass":272.13826,"relative_atomic_mass_uncertainty":0.00058,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-273","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":273,"neutrons":166,"relative_atomic_mass":273.14024,"relative_atomic_mass_uncertainty":0.0008,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-274","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":274,"neutrons":167,"relative_atomic_mass":274.14355,"relative_atomic_mass_uncertainty":0.00065,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Bh-275","atomic_number":107,"element_symbol":"Bh","nist_symbol":"Bh","mass_number":275,"neutrons":168,"relative_atomic_mass":275.14567,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-263","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":263,"neutrons":155,"relative_atomic_mass":263.12852,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-264","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":264,"neutrons":156,"relative_atomic_mass":264.128357,"relative_atomic_mass_uncertainty":0.000031,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-265","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":265,"neutrons":157,"relative_atomic_mass":265.129793,"relative_atomic_mass_uncertainty":0.000026,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-266","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":266,"neutrons":158,"relative_atomic_mass":266.130046,"relative_atomic_mass_uncertainty":0.000042,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-267","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":267,"neutrons":159,"relative_atomic_mass":267.13167,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-268","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":268,"neutrons":160,"relative_atomic_mass":268.13186,"relative_atomic_mass_uncertainty":0.0003,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-269","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":269,"neutrons":161,"relative_atomic_mass":269.13375,"relative_atomic_mass_uncertainty":0.00013,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-270","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":270,"neutrons":162,"relative_atomic_mass":270.13429,"relative_atomic_mass_uncertainty":0.00027,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-271","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":271,"neutrons":163,"relative_atomic_mass":271.13717,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-272","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":272,"neutrons":164,"relative_atomic_mass":272.1385,"relative_atomic_mass_uncertainty":0.00055,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-273","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":273,"neutrons":165,"relative_atomic_mass":273.14168,"relative_atomic_mass_uncertainty":0.0004,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-274","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":274,"neutrons":166,"relative_atomic_mass":274.1433,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-275","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":275,"neutrons":167,"relative_atomic_mass":275.14667,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-276","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":276,"neutrons":168,"relative_atomic_mass":276.14846,"relative_atomic_mass_uncertainty":0.00086,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Hs-277","atomic_number":108,"element_symbol":"Hs","nist_symbol":"Hs","mass_number":277,"neutrons":169,"relative_atomic_mass":277.1519,"relative_atomic_mass_uncertainty":0.00058,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-265","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":265,"neutrons":156,"relative_atomic_mass":265.136,"relative_atomic_mass_uncertainty":0.00048,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-266","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":266,"neutrons":157,"relative_atomic_mass":266.13737,"relative_atomic_mass_uncertainty":0.00033,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-267","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":267,"neutrons":158,"relative_atomic_mass":267.13719,"relative_atomic_mass_uncertainty":0.00054,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-268","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":268,"neutrons":159,"relative_atomic_mass":268.13865,"relative_atomic_mass_uncertainty":0.00025,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-269","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":269,"neutrons":160,"relative_atomic_mass":269.13882,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-270","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":270,"neutrons":161,"relative_atomic_mass":270.14033,"relative_atomic_mass_uncertainty":0.00018,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-271","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":271,"neutrons":162,"relative_atomic_mass":271.14074,"relative_atomic_mass_uncertainty":0.00035,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-272","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":272,"neutrons":163,"relative_atomic_mass":272.14341,"relative_atomic_mass_uncertainty":0.00052,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-273","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":273,"neutrons":164,"relative_atomic_mass":273.1444,"relative_atomic_mass_uncertainty":0.00052,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-274","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":274,"neutrons":165,"relative_atomic_mass":274.14724,"relative_atomic_mass_uncertainty":0.00038,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-275","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":275,"neutrons":166,"relative_atomic_mass":275.14882,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-276","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":276,"neutrons":167,"relative_atomic_mass":276.15159,"relative_atomic_mass_uncertainty":0.00059,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-277","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":277,"neutrons":168,"relative_atomic_mass":277.15327,"relative_atomic_mass_uncertainty":0.00082,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-278","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":278,"neutrons":169,"relative_atomic_mass":278.15631,"relative_atomic_mass_uncertainty":0.00068,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mt-279","atomic_number":109,"element_symbol":"Mt","nist_symbol":"Mt","mass_number":279,"neutrons":170,"relative_atomic_mass":279.15808,"relative_atomic_mass_uncertainty":0.00072,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-267","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":267,"neutrons":157,"relative_atomic_mass":267.14377,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-268","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":268,"neutrons":158,"relative_atomic_mass":268.14348,"relative_atomic_mass_uncertainty":0.00032,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-269","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":269,"neutrons":159,"relative_atomic_mass":269.144752,"relative_atomic_mass_uncertainty":0.000034,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-270","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":270,"neutrons":160,"relative_atomic_mass":270.144584,"relative_atomic_mass_uncertainty":0.000052,"mass_estimated":false,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-271","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":271,"neutrons":161,"relative_atomic_mass":271.14595,"relative_atomic_mass_uncertainty":0.0001,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-272","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":272,"neutrons":162,"relative_atomic_mass":272.14602,"relative_atomic_mass_uncertainty":0.00044,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-273","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":273,"neutrons":163,"relative_atomic_mass":273.14856,"relative_atomic_mass_uncertainty":0.00014,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-274","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":274,"neutrons":164,"relative_atomic_mass":274.14941,"relative_atomic_mass_uncertainty":0.00042,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-275","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":275,"neutrons":165,"relative_atomic_mass":275.15203,"relative_atomic_mass_uncertainty":0.00045,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-276","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":276,"neutrons":166,"relative_atomic_mass":276.15303,"relative_atomic_mass_uncertainty":0.00059,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-277","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":277,"neutrons":167,"relative_atomic_mass":277.15591,"relative_atomic_mass_uncertainty":0.00041,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-278","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":278,"neutrons":168,"relative_atomic_mass":278.15704,"relative_atomic_mass_uncertainty":0.00067,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-279","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":279,"neutrons":169,"relative_atomic_mass":279.1601,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-280","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":280,"neutrons":170,"relative_atomic_mass":280.16131,"relative_atomic_mass_uncertainty":0.00089,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ds-281","atomic_number":110,"element_symbol":"Ds","nist_symbol":"Ds","mass_number":281,"neutrons":171,"relative_atomic_mass":281.16451,"relative_atomic_mass_uncertainty":0.00059,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-272","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":272,"neutrons":161,"relative_atomic_mass":272.15327,"relative_atomic_mass_uncertainty":0.00025,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-273","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":273,"neutrons":162,"relative_atomic_mass":273.15313,"relative_atomic_mass_uncertainty":0.00056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-274","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":274,"neutrons":163,"relative_atomic_mass":274.15525,"relative_atomic_mass_uncertainty":0.00019,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-275","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":275,"neutrons":164,"relative_atomic_mass":275.15594,"relative_atomic_mass_uncertainty":0.00056,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-276","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":276,"neutrons":165,"relative_atomic_mass":276.15833,"relative_atomic_mass_uncertainty":0.00068,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-277","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":277,"neutrons":166,"relative_atomic_mass":277.15907,"relative_atomic_mass_uncertainty":0.00061,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-278","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":278,"neutrons":167,"relative_atomic_mass":278.16149,"relative_atomic_mass_uncertainty":0.00038,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-279","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":279,"neutrons":168,"relative_atomic_mass":279.16272,"relative_atomic_mass_uncertainty":0.00051,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-280","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":280,"neutrons":169,"relative_atomic_mass":280.16514,"relative_atomic_mass_uncertainty":0.00061,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-281","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":281,"neutrons":170,"relative_atomic_mass":281.16636,"relative_atomic_mass_uncertainty":0.00089,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-282","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":282,"neutrons":171,"relative_atomic_mass":282.16912,"relative_atomic_mass_uncertainty":0.00072,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Rg-283","atomic_number":111,"element_symbol":"Rg","nist_symbol":"Rg","mass_number":283,"neutrons":172,"relative_atomic_mass":283.17054,"relative_atomic_mass_uncertainty":0.00079,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-276","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":276,"neutrons":164,"relative_atomic_mass":276.16141,"relative_atomic_mass_uncertainty":0.00064,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-277","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":277,"neutrons":165,"relative_atomic_mass":277.16364,"relative_atomic_mass_uncertainty":0.00015,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-278","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":278,"neutrons":166,"relative_atomic_mass":278.16416,"relative_atomic_mass_uncertainty":0.00047,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-279","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":279,"neutrons":167,"relative_atomic_mass":279.16654,"relative_atomic_mass_uncertainty":0.0005,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-280","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":280,"neutrons":168,"relative_atomic_mass":280.16715,"relative_atomic_mass_uncertainty":0.00063,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-281","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":281,"neutrons":169,"relative_atomic_mass":281.16975,"relative_atomic_mass_uncertainty":0.00042,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-282","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":282,"neutrons":170,"relative_atomic_mass":282.1705,"relative_atomic_mass_uncertainty":0.0007,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-283","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":283,"neutrons":171,"relative_atomic_mass":283.17327,"relative_atomic_mass_uncertainty":0.00065,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-284","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":284,"neutrons":172,"relative_atomic_mass":284.17416,"relative_atomic_mass_uncertainty":0.00091,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Cn-285","atomic_number":112,"element_symbol":"Cn","nist_symbol":"Cn","mass_number":285,"neutrons":173,"relative_atomic_mass":285.17712,"relative_atomic_mass_uncertainty":0.0006,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-278","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":278,"neutrons":165,"relative_atomic_mass":278.17058,"relative_atomic_mass_uncertainty":0.0002,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-279","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":279,"neutrons":166,"relative_atomic_mass":279.17095,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-280","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":280,"neutrons":167,"relative_atomic_mass":280.17293,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-281","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":281,"neutrons":168,"relative_atomic_mass":281.17348,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-282","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":282,"neutrons":169,"relative_atomic_mass":282.17567,"relative_atomic_mass_uncertainty":0.00039,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-283","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":283,"neutrons":170,"relative_atomic_mass":283.17657,"relative_atomic_mass_uncertainty":0.00052,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-284","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":284,"neutrons":171,"relative_atomic_mass":284.17873,"relative_atomic_mass_uncertainty":0.00062,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-285","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":285,"neutrons":172,"relative_atomic_mass":285.17973,"relative_atomic_mass_uncertainty":0.00089,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-286","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":286,"neutrons":173,"relative_atomic_mass":286.18221,"relative_atomic_mass_uncertainty":0.00072,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Nh-287","atomic_number":113,"element_symbol":"Nh","nist_symbol":"Nh","mass_number":287,"neutrons":174,"relative_atomic_mass":287.18339,"relative_atomic_mass_uncertainty":0.00081,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fl-285","atomic_number":114,"element_symbol":"Fl","nist_symbol":"Fl","mass_number":285,"neutrons":171,"relative_atomic_mass":285.18364,"relative_atomic_mass_uncertainty":0.00047,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fl-286","atomic_number":114,"element_symbol":"Fl","nist_symbol":"Fl","mass_number":286,"neutrons":172,"relative_atomic_mass":286.18423,"relative_atomic_mass_uncertainty":0.00071,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fl-287","atomic_number":114,"element_symbol":"Fl","nist_symbol":"Fl","mass_number":287,"neutrons":173,"relative_atomic_mass":287.18678,"relative_atomic_mass_uncertainty":0.00066,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fl-288","atomic_number":114,"element_symbol":"Fl","nist_symbol":"Fl","mass_number":288,"neutrons":174,"relative_atomic_mass":288.18757,"relative_atomic_mass_uncertainty":0.00091,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Fl-289","atomic_number":114,"element_symbol":"Fl","nist_symbol":"Fl","mass_number":289,"neutrons":175,"relative_atomic_mass":289.19042,"relative_atomic_mass_uncertainty":0.0006,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mc-287","atomic_number":115,"element_symbol":"Mc","nist_symbol":"Mc","mass_number":287,"neutrons":172,"relative_atomic_mass":287.1907,"relative_atomic_mass_uncertainty":0.00052,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mc-288","atomic_number":115,"element_symbol":"Mc","nist_symbol":"Mc","mass_number":288,"neutrons":173,"relative_atomic_mass":288.19274,"relative_atomic_mass_uncertainty":0.00062,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mc-289","atomic_number":115,"element_symbol":"Mc","nist_symbol":"Mc","mass_number":289,"neutrons":174,"relative_atomic_mass":289.19363,"relative_atomic_mass_uncertainty":0.00089,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mc-290","atomic_number":115,"element_symbol":"Mc","nist_symbol":"Mc","mass_number":290,"neutrons":175,"relative_atomic_mass":290.19598,"relative_atomic_mass_uncertainty":0.00073,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Mc-291","atomic_number":115,"element_symbol":"Mc","nist_symbol":"Uup","mass_number":291,"neutrons":176,"relative_atomic_mass":291.19707,"relative_atomic_mass_uncertainty":0.00088,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lv-289","atomic_number":116,"element_symbol":"Lv","nist_symbol":"Lv","mass_number":289,"neutrons":173,"relative_atomic_mass":289.19816,"relative_atomic_mass_uncertainty":0.00057,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lv-290","atomic_number":116,"element_symbol":"Lv","nist_symbol":"Lv","mass_number":290,"neutrons":174,"relative_atomic_mass":290.19864,"relative_atomic_mass_uncertainty":0.00071,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lv-291","atomic_number":116,"element_symbol":"Lv","nist_symbol":"Lv","mass_number":291,"neutrons":175,"relative_atomic_mass":291.20108,"relative_atomic_mass_uncertainty":0.00066,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lv-292","atomic_number":116,"element_symbol":"Lv","nist_symbol":"Lv","mass_number":292,"neutrons":176,"relative_atomic_mass":292.20174,"relative_atomic_mass_uncertainty":0.00091,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Lv-293","atomic_number":116,"element_symbol":"Lv","nist_symbol":"Lv","mass_number":293,"neutrons":177,"relative_atomic_mass":293.20449,"relative_atomic_mass_uncertainty":0.0006,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ts-291","atomic_number":117,"element_symbol":"Ts","nist_symbol":"Ts","mass_number":291,"neutrons":174,"relative_atomic_mass":291.20553,"relative_atomic_mass_uncertainty":0.00068,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ts-292","atomic_number":117,"element_symbol":"Ts","nist_symbol":"Ts","mass_number":292,"neutrons":175,"relative_atomic_mass":292.20746,"relative_atomic_mass_uncertainty":0.00075,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ts-293","atomic_number":117,"element_symbol":"Ts","nist_symbol":"Ts","mass_number":293,"neutrons":176,"relative_atomic_mass":293.20824,"relative_atomic_mass_uncertainty":0.00089,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Ts-294","atomic_number":117,"element_symbol":"Ts","nist_symbol":"Uus","mass_number":294,"neutrons":177,"relative_atomic_mass":294.21046,"relative_atomic_mass_uncertainty":0.00074,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Og-293","atomic_number":118,"element_symbol":"Og","nist_symbol":"Og","mass_number":293,"neutrons":175,"relative_atomic_mass":293.21356,"relative_atomic_mass_uncertainty":0.00078,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Og-294","atomic_number":118,"element_symbol":"Og","nist_symbol":"Og","mass_number":294,"neutrons":176,"relative_atomic_mass":294.21392,"relative_atomic_mass_uncertainty":0.00071,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null},{"isotope":"Og-295","atomic_number":118,"element_symbol":"Og","nist_symbol":"Og","mass_number":295,"neutrons":177,"relative_atomic_mass":295.21624,"relative_atomic_mass_uncertainty":0.00069,"mass_estimated":true,"natural_abundance":null,"natural_abundance_uncertainty":null,"naturally_occurring":false,"standard_atomic_weight":null,"notes":null}]