Cobalt vs Rubidium
| Property | Co Cobalt | Rb Rubidium |
|---|---|---|
| Atomic number | 27 | 37 |
| Symbol | Co | Rb |
| Name | Cobalt | Rubidium |
| Category | transition-metal | alkali-metal |
| Standard Atomic Weight | 58.933194 u | 85.4678 u |
| Period | 4 | 5 |
| Group | 9 | 1 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d7 | [Kr]5s1 |
| Oxidation states | [-3, -1, 0, 1, 2, 3, 4, 5] | [-1, 1] |
| Electronegativity (Pauling) | 1.88 | 0.82 |
| Electron affinity | 0.661 eV | 0.4859 eV |
| Density | 8860 kg/m³ | 1530 kg/m³ |
| Melting point | 1494.85 °C | 39.31 °C |
| Boiling point | 2926.85 °C | 687.85 °C |
| Discovery year | 1735 | 1861 |