Krypton vs Rubidium
| Property | Kr Krypton | Rb Rubidium |
|---|---|---|
| Atomic number | 36 | 37 |
| Symbol | Kr | Rb |
| Name | Krypton | Rubidium |
| Category | noble-gas | alkali-metal |
| Standard Atomic Weight | 83.798 u | 85.4678 u |
| Period | 4 | 5 |
| Group | 18 | 1 |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ar]4s23d104p6 | [Kr]5s1 |
| Oxidation states | [0, 1, 2] | [-1, 1] |
| Electronegativity (Pauling) | 3 | 0.82 |
| Electron affinity | -1 eV | 0.4859 eV |
| Density | 3.733 kg/m³ | 1530 kg/m³ |
| Melting point | -157.36 °C | 39.31 °C |
| Boiling point | -153.42 °C | 687.85 °C |
| Discovery year | 1898 | 1861 |