| Rubidium ✕ | |
|---|---|
| Symbol | Rb |
| Atomic number | 37 |
| Chemical property | Alkali metal |
| Origin o the name | the Latin rubidus, 'deep red' |
| Group | 1 |
| Period | 5 |
| Atomic weight (u) | 85.4678 |
| Atomic weight uncertainty (u) | 0.0003 |
| Density (g/cm³) | 1.532 |
| Melting point (K) | 312.46 |
| Boiling point (K) | 961 |
| Heat capacity (J/(g·K)) | 0.363 |
| Electro-negativity | 0.82 |
| Abundance in earth's crust (mg/kg) | 90 |