77Ir192.22
Iridium (Ir)
Element 77 · Transition metal
Iridium (Ir) is a chemical element with atomic number 77. It is classified as a transition metal in period 6, group 9 of the periodic table (the d-block). Its standard atomic weight is 192.22 u and its ground-state electron configuration is [Xe] 4f¹⁴ 5d⁷ 6s².
Iridium facts
| Atomic number (Z) | 77 |
|---|---|
| Symbol | Ir |
| Standard atomic weight | 192.22 u |
| Category | Transition metal |
| Group | 9 |
| Period | 6 |
| Block | d-block |
| Electron configuration | [Xe] 4f¹⁴ 5d⁷ 6s² |
| Electronegativity (Pauling) | 2.2 |
| State at 20 °C | Solid |
| Protons / electrons | 77 / 77 |
| Neutrons (most common isotope, approx.) | 115 |
| Molar mass | 192.22 g/mol |