Oxygen vs Neptunium
| Property | O Oxygen | Np Neptunium |
|---|---|---|
| Atomic number | 8 | 93 |
| Symbol | O | Np |
| Name | Oxygen | Neptunium |
| Category | nonmetal | actinide |
| Standard Atomic Weight | 15.9994 u | 237 u |
| Period | 2 | 7 |
| Group | 16 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [He]2s22p4 | [Rn]7s25f46d1 |
| Oxidation states | [-2, -1, 0, 1, 2] | [2, 3, 4, 5, 6, 7] |
| Electronegativity (Pauling) | 3.44 | 1.36 |
| Electron affinity | 1.4611 eV | 0.48 eV |
| Density | 1.429 kg/m³ | 2.025000e+4 kg/m³ |
| Melting point | -218.79 °C | 643.85 °C |
| Boiling point | -182.95 °C | 3901.85 °C |
| Discovery year | 1771 | 1940 |