| Iridium | |
| Electrons per shell | 2,8,18,32,15,2 |
| Electron Configuration | [Xe] 4f14 5d7 6s2 |
| Ground state | 4F9/2 |
| Atomic Volume | 8.54 cm3 mol-1 |
| Electronegativity | 2.20 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 2.3 x 10-9 |
| Molar magnetic susceptibility | 4.42 x 10-10 |
| Speed of sound | 4825 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 628 kJ mol-1 @25°C |
| Enthalpy of Fusion | 26.4 kJ mol-1 |
| Enthalpy of Vaporisation | 612.1 kJ mol-1 |
| Heat Capacity | 25.10 J mol-1 K-1 |
| Thermal Conductivity | 147 W m-1 K-1 |
| Thermal Expansion | 6.4 μm m-1 K-1 |
| Hardness |
|
| Brinell hardness | 1670 MPa |
| Mohs hardness | 6.5 |
| Vickers hardness | 1760 MPa |
| Elastic Properties |
|
| Bulk modulus | 320 GPa |
| Poisson ratio | 0.26 |
| Shear modulus | 210 GPa |
| Young's modulus | 528 GPa |
| Electrical Properties |
|
| Electrical resistivity | 4.7 x 10-8 Ω m |
| Electrical conductivity | 0.197 106/cm Ω |
| Chemical Properties |
|
| Electrochemical Equivalent | 1.793 g Ah-1 |
| Electron Work Function | 5.27 eV |
| Valence Electron Potential (-eV) | 92.2 |
| Ionization Potential | |
 First
|
9.1 |
| Energy Levels |
|
| Kα1 (intensity 100) |
64.8956 KeV |
| Kα2 (intensity 50) |
63.2867 KeV |
| Kβ1 (intensity 26.4) |
73.5608 KeV |
| Kβ2 (intensity 10.7) |
74.0996 KeV |
| Kβ3 (intensity 10.2) |
73.5896 KeV |
| Lα1 (intensity 100) |
9.1751 KeV |
| Lα2 (intensity 10) |
9.0995 KeV |
| Lβ1 (intensity 38) |
10.7083 KeV |
| Lβ2 (intensity 18) |
10.9203 KeV |
| Lβ3 (intensity 6.5) |
10.8653 KeV |
| Lβ4 (intensity 4) |
10.5094 KeV |
| Lγ1 (intensity 6) |
12.5126 KeV |
| Lγ2 (intensity 2) |
12.8383 KeV |
| Lγ3 (intensity 2) |
9.647 KeV |
| Ll (intensity 4.5) |
8.0423 KeV |
| Atomic Radii |
|
| Empirical
|
135 pm |
| Bohr Radius
|
180 pm |
| Covalent Radius
|
137 pm |
| Van der Waals
|
No data. |
| Triple covalent
|
107 pm |
| Metallic
|
135.5 pm |
| Oxidation States |
|
| Main
|
Ir+3, Ir+4 |
| Other
|
Ir-1, Ir0, Ir+1, Ir+2, Ir+5, Ir+6 |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
880 |
| M+ - M2+ |
1680 |
| M2+ - M3+ |
2600 |
| M3+ - M4+ |
3800 |
| M4+ - M5+ |
5500 |
| M5+ - M6+ |
6900 |
| M6+ - M7+ |
8500 |
| M7+ - M8+ |
10000 |
| M8+ - M9+ |
11700 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 2713 | 2957 | 3252 | 3614 | 4069 | 4659 |
| Crystal Structure |
|
| Structure
|
Cubic close packed |
 |
a = 383.9 pm |
| b = 383.9 pm | |
| c = 383.9 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |