Rubidium vs Strontium
| Property | Rb Rubidium | Sr Strontium |
|---|---|---|
| Atomic number | 37 | 38 |
| Symbol | Rb | Sr |
| Name | Rubidium | Strontium |
| Category | alkali-metal | alkaline-earth-metal |
| Standard Atomic Weight | 85.4678 u | 87.62 u |
| Period | 5 | 5 |
| Group | 1 | 2 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s1 | [Kr]5s2 |
| Oxidation states | [-1, 1] | [1, 2] |
| Electronegativity (Pauling) | 0.82 | 0.95 |
| Electron affinity | 0.4859 eV | 0.052 eV |
| Density | 1530 kg/m³ | 2640 kg/m³ |
| Melting point | 39.31 °C | 776.85 °C |
| Boiling point | 687.85 °C | 1381.85 °C |
| Discovery year | 1861 | 1792 |