Astatine vs Neptunium
| Property | At Astatine | Np Neptunium |
|---|---|---|
| Atomic number | 85 | 93 |
| Symbol | At | Np |
| Name | Astatine | Neptunium |
| Category | halogen | actinide |
| Standard Atomic Weight | 210 u | 237 u |
| Period | 6 | 7 |
| Group | 17 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d106p5 | [Rn]7s25f46d1 |
| Oxidation states | [-1, 1, 3, 5, 7] | [2, 3, 4, 5, 6, 7] |
| Electronegativity (Pauling) | 2.2 | 1.36 |
| Electron affinity | 2.391 eV | 0.48 eV |
| Density | 7000 kg/m³ | 2.025000e+4 kg/m³ |
| Melting point | 301.85 °C | 643.85 °C |
| Boiling point | -273.15 °C | 3901.85 °C |
| Discovery year | 1940 | 1940 |