Rubidium vs Cesium
Pick up to 3 elements and see how they stack up.
| Property | Rubidium | Cesium |
|---|---|---|
| Atomic number | 37 | 55 |
| Atomic mass | 85.468 | 132.91 |
| Electronegativity | 0.82 | 0.79 |
| Melting point | 312.45 K (39.3 °C) | 301.59 K (28.4 °C) |
| Boiling point | 961 K (687.8 °C) | 944 K (670.8 °C) |
| Density | 1.532 g/cm³ | 1.93 g/cm³ |
| Atomic radius | 303 pm | 343 pm |
| Ionization energy | 4.177 eV | 3.894 eV |
| Discovered | 1861 | 1860 |
| Category | Alkali metal | Alkali metal |
| State at room temp. | Solid | Solid |
| Block | s | s |
| Group | 1 | 1 |
| Period | 5 | 6 |
| Valence electrons | 1 | 1 |
| Common charges | +1 | +1 |
| Electron configuration | [Kr] 5s1 | [Xe] 6s1 |