Erbium vs Astatine
| Property | Er Erbium | At Astatine |
|---|---|---|
| Atomic number | 68 | 85 |
| Symbol | Er | At |
| Name | Erbium | Astatine |
| Category | lanthanide | halogen |
| Standard Atomic Weight | 167.259 u | 210 u |
| Period | 6 | 6 |
| Group | N/A | 17 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f12 | [Xe]6s24f145d106p5 |
| Oxidation states | [0, 1, 2, 3] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 1.24 | 2.2 |
| Electron affinity | 0.312 eV | 2.391 eV |
| Density | 9070 kg/m³ | 7000 kg/m³ |
| Melting point | 1528.85 °C | 301.85 °C |
| Boiling point | 2867.85 °C | -273.15 °C |
| Discovery year | 1843 | 1940 |