Cesium vs Thallium
| Property | Cs Cesium | Tl Thallium |
|---|---|---|
| Atomic number | 55 | 81 |
| Symbol | Cs | Tl |
| Name | Cesium | Thallium |
| Category | alkali-metal | post-transition-metal |
| Standard Atomic Weight | 132.905452 u | 204.3835 u |
| Period | 6 | 6 |
| Group | 1 | 13 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s1 | [Xe]6s24f145d106p1 |
| Oxidation states | [-1, 1] | [-5, -2, -1, 1, 2, 3] |
| Electronegativity (Pauling) | 0.79 | 1.62 |
| Electron affinity | 0.4716 eV | 0.377 eV |
| Density | 1930 kg/m³ | 1.180000e+4 kg/m³ |
| Melting point | 28.44 °C | 303.85 °C |
| Boiling point | 670.85 °C | 1472.85 °C |
| Discovery year | 1860 | 1861 |