Iridium vs Francium
| Property | Ir Iridium | Fr Francium |
|---|---|---|
| Atomic number | 77 | 87 |
| Symbol | Ir | Fr |
| Name | Iridium | Francium |
| Category | transition-metal | alkali-metal |
| Standard Atomic Weight | 192.217 u | 223 u |
| Period | 6 | 7 |
| Group | 9 | 1 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d7 | [Rn]7s1 |
| Oxidation states | [-3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9] | [1] |
| Electronegativity (Pauling) | 2.2 | 0.7 |
| Electron affinity | 1.565 eV | 0.491 eV |
| Density | 2.256220e+4 kg/m³ | 1870 kg/m³ |
| Melting point | 2445.85 °C | 26.85 °C |
| Boiling point | 4427.85 °C | -273.15 °C |
| Discovery year | 1803 | 1939 |