Atomic number 76
Osmium
Transition metal
Quick facts
- Atomic mass
- 190.23
- Group
- 8
- Period
- 6
- State (STP)
- solid
- Electronegativity
- 2.20
- Common ox. states
- +4, +8
Properties
Electron configuration
[Xe] 4f¹⁴ 5d⁶ 6s²
- Ionization energy
- 840.0 kJ/mol
- Electron affinity
- 106.1 kJ/mol
- Melting point
- 3306.00 K (3032.8 °C)
- Boiling point
- 5285.00 K (5011.9 °C)
How it bonds
Osmium is the densest stable element (22.59 g/cm³). Most stable +4, with +8 in OsO₄ — a volatile, toxic, and famously useful oxidizer in organic chemistry (it cleaves alkenes to diols).