Cesium vs Iridium
| Property | Cs Cesium | Ir Iridium |
|---|---|---|
| Atomic number | 55 | 77 |
| Symbol | Cs | Ir |
| Name | Cesium | Iridium |
| Category | alkali-metal | transition-metal |
| Standard Atomic Weight | 132.905452 u | 192.217 u |
| Period | 6 | 6 |
| Group | 1 | 9 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s1 | [Xe]6s24f145d7 |
| Oxidation states | [-1, 1] | [-3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| Electronegativity (Pauling) | 0.79 | 2.2 |
| Electron affinity | 0.4716 eV | 1.565 eV |
| Density | 1930 kg/m³ | 2.256220e+4 kg/m³ |
| Melting point | 28.44 °C | 2445.85 °C |
| Boiling point | 670.85 °C | 4427.85 °C |
| Discovery year | 1860 | 1803 |