| Osmium | |
| Electrons per shell | 2,8,18,32,14,2 |
| Electron Configuration | [Xe] 4f14 5d6 6s2 ![]() |
| Ground state | 5D4 |
| Atomic Volume | 8.49 cm3 mol-1 |
| Electronegativity | 2.2 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 6 x 10-10 |
| Molar magnetic susceptibility | 1.1 x 10-10 |
| Speed of sound | 4940 m s-1 |
Thermal Properties |
|
| Enthalpy of Atomization | 669 kJ mol-1 @25°C |
| Enthalpy of Fusion | 29.3 kJ mol-1 |
| Enthalpy of Vaporisation | 738 kJ mol-1 |
| Heat Capacity | 24.7 J mol-1 K-1 |
| Thermal Conductivity | 87.6 W m-1 K-1 |
| Thermal Expansion | 5.1 μm m-1 K-1 |
| Critcal Temperature | No data. |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Hardness |
|
| Brinell hardness | 3920 MPa |
| Mohs hardness | 7.0 |
Elastic Properties |
|
| Bulk modulus | 462 GPa |
| Poisson ratio | 0.25 |
| Shear modulus | 222 GPa |
Electrical Properties |
|
| Electrical resistivity | 8.1 x 10-8 Ω m |
| Electrical conductivity | 0.109 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 1.774 g Ah-1 |
| Electron Work Function | 4.83 eV |
| Valence Electron Potential (-eV) | 91.4 |
| Ionization Potential | |
| 8.7 | |
Energy Levels |
|
| 63.0005 KeV | |
| 61.4867 KeV | |
| 71.413 KeV | |
| 72.1286 KeV | |
| 71.3991 KeV | |
| 8.9117 KeV | |
| 8.841 KeV | |
| 10.3553 KeV | |
| 10.5985 KeV | |
| 10.5074 KeV | |
| 10.1738 KeV | |
| 12.0953 KeV | |
| 12.4182 KeV | |
| 9.334 KeV | |
| 7.8206 KeV | |
Atomic Radii |
|
| 130 pm | |
| 185 pm | |
| 128 pm | |
| No data. | |
| 109 pm | |
| 135 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 4 | VI | 0.77 | 0.63 | RM |
| 5 | VI | 0.715 | 0.575 | E |
| 6 | V | 0.63 | 0.49 | |
| VI | 0.685 | 0.545 | E | |
| 7 | VI | 0.665 | 0.525 | E |
| 8 | IV | 0.53 | 0.39 | |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
Oxidation States |
|
| Os+4 | |
| Os-2, Os0, Os+1, Os+2, Os+3, Os+5, Os+6, Os+7, Os+8 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 840 | |
| 1600 | |
| 2400 | |
| 3900 | |
| 5200 | |
| 6600 | |
| 8100 | |
| 9500 | |
Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 3160 | 3423 | 3751 | 4148 | 4638 | 5256 |
Crystal Structure |
|
| Hexagonal close packed | |
![]() |
a = 273.44 pm |
| b = 273.44 pm | |
| c = 431.73 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |