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Iridium

Metalsolid
Symbol: Ir
Atomic number: 77
Atomic mass: 192.22
Group: Transition Metal
CAS-number: 7439-88-5

Physical data
Isotopes
Other info
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Physical data

Electronic data

Shells: 2, 8, 18, 32, 15, 2
Orbitals: [Xe] 4f14 5d7 6s2
Electronegativity: 2.2, 1.5
1. Ionization potential: 9.1 eV
2. Ionization potential: -- eV
3. Ionization potential: -- eV
Oxidation states: 6, 4, 3, 2, 1, 0, -1
Electrical conductivity: 0.197 10^6

Thermal data

Melting point: 2410 °C
Boiling point: 4130 °C
Specific heat: 0.130 J/gK
Heat of fusion: 26.10 kJ/mol
Heat of vaporization: 604.0 kJ/mol
Thermal conductivity: 1.47 W/cmK

Steric data

Atomic radius: 1.87 Å
Ionic radius: 0.63 Å (+4)
Covalent radius: 1.27 Å
Atomic volume: 8.54 cm³/mol
Density (293 K): 22.42 g/cm³
Crystal structure: cubic face centered
cubic face centered

Isotopes

NuclideAbundance [%]MassSpinHalflifeDecay modeDecay tree
188Ir 0 188 2 1.72d EC, β+ View
189Ir 0 189 3/2 13.2d EC View
190Ir 0 190 4 11.8d EC View
190Irm 0 190 7 1.20h IT View
190m2Ir 0 190 11 3.20h EC, β+, IT View
191Ir 37.3 190.961 3/2 -- --
191Irm 0 191 11/2 4.93s IT View
192Ir 0 192 4 73.83d β-, EC View
193Ir 62.7 192.963 3/2 -- --
193Irm 0 193 11/2 10.53d IT View
194Ir 0 194 1 19.3h β- View
194Irm 0 194 11 170d β- View

Other info

Name origin:Latin: iris (rainbow).
Description:Heavy, brittle, white metal.
Discovered by:S.Tenant, A.F.Fourcory, L.N.Vauquelin, H.V.Collet-Descoltils
Year:1804
Place:England/France
Sources:Found in gravel deposits with platinum.
Use(s):Used with osmium to tip gold pen points, to make crucible and special containers. Also to make alloys used for standard weights and measures, and heat-resistant alloys. Also as hardening agent for platinum.