Promethium vs Iridium
| Property | Pm Promethium | Ir Iridium |
|---|---|---|
| Atomic number | 61 | 77 |
| Symbol | Pm | Ir |
| Name | Promethium | Iridium |
| Category | lanthanide | transition-metal |
| Standard Atomic Weight | 145 u | 192.217 u |
| Period | 6 | 6 |
| Group | N/A | 9 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f5 | [Xe]6s24f145d7 |
| Oxidation states | [2, 3] | [-3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| Electronegativity (Pauling) | N/A | 2.2 |
| Electron affinity | 0.129 eV | 1.565 eV |
| Density | 7260 kg/m³ | 2.256220e+4 kg/m³ |
| Melting point | 1041.85 °C | 2445.85 °C |
| Boiling point | 2999.85 °C | 4427.85 °C |
| Discovery year | 1902 | 1803 |