Cobalt vs Selenium
| Property | Co Cobalt | Se Selenium |
|---|---|---|
| Atomic number | 27 | 34 |
| Symbol | Co | Se |
| Name | Cobalt | Selenium |
| Category | transition-metal | nonmetal |
| Standard Atomic Weight | 58.933194 u | 78.971 u |
| Period | 4 | 4 |
| Group | 9 | 16 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d7 | [Ar]4s23d104p4 |
| Oxidation states | [-3, -1, 0, 1, 2, 3, 4, 5] | [-2, -1, 0, 1, 2, 3, 4, 5, 6] |
| Electronegativity (Pauling) | 1.88 | 2.55 |
| Electron affinity | 0.661 eV | 2.0206 eV |
| Density | 8860 kg/m³ | 4809 kg/m³ |
| Melting point | 1494.85 °C | 220.5 °C |
| Boiling point | 2926.85 °C | 684.85 °C |
| Discovery year | 1735 | 1817 |