Sodium vs Rubidium
| Property | Na Sodium | Rb Rubidium |
|---|---|---|
| Atomic number | 11 | 37 |
| Symbol | Na | Rb |
| Name | Sodium | Rubidium |
| Category | alkali-metal | alkali-metal |
| Standard Atomic Weight | 22.989769 u | 85.4678 u |
| Period | 3 | 5 |
| Group | 1 | 1 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ne]3s1 | [Kr]5s1 |
| Oxidation states | [-1, 0, 1] | [-1, 1] |
| Electronegativity (Pauling) | 0.93 | 0.82 |
| Electron affinity | 0.5479 eV | 0.4859 eV |
| Density | 970 kg/m³ | 1530 kg/m³ |
| Melting point | 97.8 °C | 39.31 °C |
| Boiling point | 882.85 °C | 687.85 °C |
| Discovery year | 1807 | 1861 |