Cesium vs Astatine
| Property | Cs Cesium | At Astatine |
|---|---|---|
| Atomic number | 55 | 85 |
| Symbol | Cs | At |
| Name | Cesium | Astatine |
| Category | alkali-metal | halogen |
| Standard Atomic Weight | 132.905452 u | 210 u |
| Period | 6 | 6 |
| Group | 1 | 17 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s1 | [Xe]6s24f145d106p5 |
| Oxidation states | [-1, 1] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 0.79 | 2.2 |
| Electron affinity | 0.4716 eV | 2.391 eV |
| Density | 1930 kg/m³ | 7000 kg/m³ |
| Melting point | 28.44 °C | 301.85 °C |
| Boiling point | 670.85 °C | -273.15 °C |
| Discovery year | 1860 | 1940 |