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iron
Image: Wikimedia Commons

iron

Chemical element with symbol Fe and atomic number 26

Chemical elementchemical elementQ677

Also known as element 26

Symbol
Atomic number
Mass
Melting point
Boiling point
Density
  • 7.874 g/cm³
Discovered by
  • unknown
Discovered
  • 5th millennium BCE

Overview

All data

482 statements · 12% with external sources · numbers in brackets are citations

Oxidation state
  • 2
  • 3
  • -2
  • -1
  • 1
  • 4
  • 5
  • 6
Show 3 more
  • -4
  • 0
  • 7
Subclass of
Magnetic ordering
Canonical SMILES
Formula
Medical condition treated
Permanent duplicated item
Thermal conductivity
  • 84 watt per metre kelvin
Subject has role
Different from
Relative permeability
  • 200,000
Embodied energy
  • 25 megajoule per kilogram
Has characteristic
Unicode character
Electronegativity
  • 1.83
Part of
Found in taxon
Show 6 more
IMA Mineral Symbol
Ionic radius
  • 0.63 ångström charge number: 2 · coordination number: 4
  • 0.61 ångström charge number: 2 · coordination number: 6
  • 0.92 ångström charge number: 2 · coordination number: 8
  • 0.49 ångström charge number: 3 · coordination number: 4
  • 0.55 ångström charge number: 3 · coordination number: 6
  • 0.78 ångström charge number: 3 · coordination number: 8
Electron configuration
  • [Ar] 3d⁶ 4s²
Associated hazard
Has use
Bulk modulus
  • 207B Pa
Shear modulus
  • 67.6B Pa
Poisson's ratio
  • 0.353
Electrical conductivity
  • 10M siemens per metre
Specific heat capacity
  • 449 joule per kilogram kelvin
Speed of sound
  • 4,910 m/s
Electrical resistivity
  • 9.61e-8 ohm metre
Standard enthalpy of formation
  • 415.47 kilojoule per mole state of matter: gas
  • 12.4 kilojoule per mole state of matter: liquid
Standard molar entropy
  • 180.49 joule per mole kelvin state of matter: gas
  • 34.76 joule per mole kelvin state of matter: liquid
Mohs' hardness
  • 4
Linear thermal expansion coefficient
  • 12.07 micrometre per metre kelvin temperature: 20°C
Ionization energy
IPA transcription
Crystal system
Atomic radius
  • 126 picometre
  • 140 picometre
Covalent radius
  • 132 picometre
  • 142 picometre

On other databases

130 identifiers linking iron across the web's reference databases