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polonium

Chemical element with symbol Po and atomic number 84

Also known as element 84 · 84Po · Po

Symbol: Po
1
Sources
1.Stated in Atomic weights of the elements 2009 (IUPAC Technical Report)
View statement on Wikidata ↗
Atomic number: 84
Mass: 208.9824 Da
1
Sources
1.physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=&ascii=ascii2&isotype=allRetrieved 2026-09-19
View statement on Wikidata ↗
Melting point: 527 K
Boiling point: 1,235 K
Density: 9,196 kg/m³
Discovered by: Marie Curie
, Pierre Curie
Discovered: 1898

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Polonium is a chemical element; it has symbol Po and atomic number 84. A rare and highly radioactive metal with no stable isotopes, polonium is a chalcogen and chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbours in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 in uranium ores, as it is the penultimate daughter of natural uranium-238. Though two longer-lived isotopes exist, they are much more difficult to produce. Today, polonium is usually produced in milligram quantities by the neutron irradiation of bismuth. Due to its intense radioactivity, which results in the radiolysis of chemical bonds and radioactive self-heating, its chemistry has mostly been investigated on the trace scale only.

Overview

All data

114 statements · 24% with external sources · numbers in brackets are citations

Named after: Poland
Subclass of: post-transition metal
group 16 follows: tellurium · followed by: livermorium
p-block
Canonical SMILES: [Po]
1
Sources
1.Stated in PubChem“POLONIUM”Retrieved 2016-11-20
View statement on Wikidata ↗
Formula: Po
1
Sources
1.Stated in PubChem“POLONIUM”Retrieved 2016-11-20
View statement on Wikidata ↗
Unicode character: 釙
1
Sources
1.cns11643.gov.tw/wordView.jsp?ID=88159Retrieved 2019-07-13
View statement on Wikidata ↗
Electronegativity: 2
Part of: period 6 follows: bismuth · followed by: astatine
group 16 follows: tellurium · followed by: livermorium
Ionic radius: 0.97 ångström charge number: 4 · coordination number: 6
Different from: Element 84
Thermal conductivity: 20 watt per metre kelvin
Electrical conductivity: 2,500,000 siemens per metre
Linear thermal expansion coefficient: 23.5 micrometre per metre kelvin temperature: 25°C
Ionization energy: 8.4181 eV
1
Sources
1.“NIST Atomic Spectra Database, Ionization Energies”physics.nist.gov/asdRetrieved 2026-09-18
View statement on Wikidata ↗
Electron configuration: [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p⁴
1
Sources
1.physics.nist.gov/asdRetrieved 2026-09-19
View statement on Wikidata ↗
IPA transcription: pəˈloʊniəm language: English
Oxidation state: -2
2
4
5
6
Crystal system: cubic crystal system
Atomic radius: 190 picometre
Covalent radius: 140 picometre

On other databases

65 identifiers linking polonium across the web's reference databases

Data quality

114

statements

24%

externally sourced

Source last edited October 3, 2026. AIDB refreshes this page daily.

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AIDB. (2026). polonium (Q979). Retrieved from https://aidb.si/e/polonium-Q979