Cesium vs Roentgenium
| Property | Cs Cesium | Rg Roentgenium |
|---|---|---|
| Atomic number | 55 | 111 |
| Symbol | Cs | Rg |
| Name | Cesium | Roentgenium |
| Category | alkali-metal | transition-metal |
| Standard Atomic Weight | 132.905452 u | 281 u |
| Period | 6 | 7 |
| Group | 1 | 11 |
| Block | s | s |
| Phase at STP | solid | N/A |
| Electron configuration | [Xe]6s1 | [Rn] 7s2 5f14 6d9(predicted) |
| Oxidation states | [-1, 1] | [-1, 1, 3, 5] |
| Electronegativity (Pauling) | 0.79 | N/A |
| Electron affinity | 0.4716 eV | 1.6 eV |
| Density | 1930 kg/m³ | 2.870000e+4 kg/m³ |
| Melting point | 28.44 °C | -273.15 °C |
| Boiling point | 670.85 °C | -273.15 °C |
| Discovery year | 1860 | 1994 |