Osmium vs Neptunium
| Property | Os Osmium | Np Neptunium |
|---|---|---|
| Atomic number | 76 | 93 |
| Symbol | Os | Np |
| Name | Osmium | Neptunium |
| Category | transition-metal | actinide |
| Standard Atomic Weight | 190.23 u | 237 u |
| Period | 6 | 7 |
| Group | 8 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d6 | [Rn]7s25f46d1 |
| Oxidation states | [-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8] | [2, 3, 4, 5, 6, 7] |
| Electronegativity (Pauling) | 2.2 | 1.36 |
| Electron affinity | 1.1 eV | 0.48 eV |
| Density | 2.258720e+4 kg/m³ | 2.025000e+4 kg/m³ |
| Melting point | 3032.85 °C | 643.85 °C |
| Boiling point | 5011.85 °C | 3901.85 °C |
| Discovery year | 1803 | 1940 |