Beryllium vs Astatine
| Property | Be Beryllium | At Astatine |
|---|---|---|
| Atomic number | 4 | 85 |
| Symbol | Be | At |
| Name | Beryllium | Astatine |
| Category | alkaline-earth-metal | halogen |
| Standard Atomic Weight | 9.012183 u | 210 u |
| Period | 2 | 6 |
| Group | 2 | 17 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [He]2s2 | [Xe]6s24f145d106p5 |
| Oxidation states | [0, 1, 2] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 1.57 | 2.2 |
| Electron affinity | -0.52 eV | 2.391 eV |
| Density | 1850 kg/m³ | 7000 kg/m³ |
| Melting point | 1286.85 °C | 301.85 °C |
| Boiling point | 2470.85 °C | -273.15 °C |
| Discovery year | 1797 | 1940 |