Cobalt vs Actinium
| Property | Co Cobalt | Ac Actinium |
|---|---|---|
| Atomic number | 27 | 89 |
| Symbol | Co | Ac |
| Name | Cobalt | Actinium |
| Category | transition-metal | actinide |
| Standard Atomic Weight | 58.933194 u | 227 u |
| Period | 4 | 7 |
| Group | 9 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d7 | [Rn]7s26d1 |
| Oxidation states | [-3, -1, 0, 1, 2, 3, 4, 5] | [3] |
| Electronegativity (Pauling) | 1.88 | 1.1 |
| Electron affinity | 0.661 eV | 0.35 eV |
| Density | 8860 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | 1494.85 °C | 1050.85 °C |
| Boiling point | 2926.85 °C | 3197.85 °C |
| Discovery year | 1735 | 1899 |