Astatine vs Fermium
| Property | At Astatine | Fm Fermium |
|---|---|---|
| Atomic number | 85 | 100 |
| Symbol | At | Fm |
| Name | Astatine | Fermium |
| Category | halogen | actinide |
| Standard Atomic Weight | 210 u | 257 u |
| Period | 6 | 7 |
| Group | 17 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d106p5 | [Rn] 5f12 7s2 |
| Oxidation states | [-1, 1, 3, 5, 7] | [2, 3] |
| Electronegativity (Pauling) | 2.2 | 1.3 |
| Electron affinity | 2.391 eV | 0.339 eV |
| Density | 7000 kg/m³ | 9700 kg/m³ |
| Melting point | 301.85 °C | 1526.85 °C |
| Boiling point | -273.15 °C | -273.15 °C |
| Discovery year | 1940 | 1952 |