77 Ir
Transition metal
Iridium
Linked to dinosaur extinction.
Properties of Iridium
- Atomic number (Z)
- 77
- Symbol
- Ir
- Atomic mass
- 192.22 g/mol
- Category
- Transition metal
- Group
- 9
- Period
- 6
- Electron configuration
- [Xe] 4f¹⁴ 5d⁷ 6s²
- Electronegativity (Pauling)
- 2.2
- Atomic radius
- 180 pm
- First ionization energy
- 880 kJ/mol
- Melting point
- 2719 K (2445.8 °C)
- Boiling point
- 4701 K (4427.9 °C)
- Density
- 22.56 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1803