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iridium
Image: Wikimedia Commons

iridium

Chemical element with symbol Ir and atomic number 77

Chemical elementchemical elementQ877

Also known as element 77 · Ir

Symbol
Atomic number
  • 77
Mass
Melting point
  • 2,739 K
Boiling point
  • 4,403 K
Density
  • 22,304.4 kg/m³
Discovered by
Discovered
  • 1803

Overview

All data

147 statements · 22% with external sources · numbers in brackets are citations

Named after
Canonical SMILES
Formula
Subclass of
Electronegativity
  • 2.2
Location of discovery
Unicode character
Part of
Different from
Ionic radius
  • 0.68 ångström charge number: 3 · coordination number: 6
  • 0.63 ångström charge number: 4 · coordination number: 6
  • 0.57 ångström charge number: 5 · coordination number: 6
Space group
Crystal system
Bulk modulus
  • 345B Pa
Shear modulus
  • 209B Pa
Poisson's ratio
  • 0.248
Thermal conductivity
  • 150 watt per metre kelvin
Electrical conductivity
  • 19.7M siemens per metre
Speed of sound
  • 4,825 m/s
Electrical resistivity
  • 4.71e-8 ohm metre
Point group
Mohs' hardness
  • 6.5
Has characteristic
Linear thermal expansion coefficient
  • 6.47 micrometre per metre kelvin temperature: 20°C
Ionization energy
Electron configuration
IPA transcription
Oxidation state
  • 1
  • 3
  • 4
  • -3
  • -2
  • -1
  • 0
  • 2
Show 5 more
  • 5
  • 6
  • 7
  • 8
  • 9
Atomic radius
  • 135 picometre
Covalent radius
  • 141 picometre

On other databases

66 identifiers linking iridium across the web's reference databases