Potassium vs Cesium
| Property | K Potassium | Cs Cesium |
|---|---|---|
| Atomic number | 19 | 55 |
| Symbol | K | Cs |
| Name | Potassium | Cesium |
| Category | alkali-metal | alkali-metal |
| Standard Atomic Weight | 39.0983 u | 132.905452 u |
| Period | 4 | 6 |
| Group | 1 | 1 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s1 | [Xe]6s1 |
| Oxidation states | [-1, 1] | [-1, 1] |
| Electronegativity (Pauling) | 0.82 | 0.79 |
| Electron affinity | 0.5014 eV | 0.4716 eV |
| Density | 890 kg/m³ | 1930 kg/m³ |
| Melting point | 63.38 °C | 28.44 °C |
| Boiling point | 758.85 °C | 670.85 °C |
| Discovery year | 1807 | 1860 |