Osmium vs Actinium
| Property | Os Osmium | Ac Actinium |
|---|---|---|
| Atomic number | 76 | 89 |
| Symbol | Os | Ac |
| Name | Osmium | Actinium |
| Category | transition-metal | actinide |
| Standard Atomic Weight | 190.23 u | 227 u |
| Period | 6 | 7 |
| Group | 8 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d6 | [Rn]7s26d1 |
| Oxidation states | [-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8] | [3] |
| Electronegativity (Pauling) | 2.2 | 1.1 |
| Electron affinity | 1.1 eV | 0.35 eV |
| Density | 2.258720e+4 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | 3032.85 °C | 1050.85 °C |
| Boiling point | 5011.85 °C | 3197.85 °C |
| Discovery year | 1803 | 1899 |