Cobalt vs Nickel
Side-by-side comparison of Cobalt (Co, element 27) and Nickel (Ni, element 28) by atomic structure and physical properties.
| Property | Co Cobalt | Ni Nickel |
|---|---|---|
| Atomic number | 27 | 28 |
| Symbol | Co | Ni |
| Name | Cobalt | Nickel |
| Category | transition-metal | transition-metal |
| Standard Atomic Weight | 58.933194 u | 58.6934 u |
| Period | 4 | 4 |
| Group | 9 | 10 |
| Block | d | d |
| Phase at STP | Solid | Solid |
| Electron configuration | [Ar]3d74s2 | [Ar]3d84s2 |
| Oxidation states | [-3, -1, 0, 1, 2, 3, 4, 5] | [-2, -1, 0, 1, 2, 3, 4] |
| Electronegativity (Pauling) | 1.88 | 1.91 |
| Electron affinity | 0.661 eV | 1.156 eV |
| Density | 8860 kg/m³ | 8912 kg/m³ |
| Melting point | 1494.85 °C | 1454.85 °C |
| Boiling point | 2926.85 °C | 2912.85 °C |
| Discovery year | 1735 | 1751 |
Key Differences
| Property | Co Cobalt | Ni Nickel |
|---|---|---|
| Standard Atomic Weight | 58.933194 u ↑ higher | 58.6934 u ↓ lower |
| Density | 8860 kg/m³ ↓ lower | 8912 kg/m³ ↑ higher |
| Melting point | 1494.85 °C ↑ higher | 1454.85 °C ↓ lower |
| Boiling point | 2926.85 °C ↑ higher | 2912.85 °C ↓ lower |
| Electronegativity (Pauling) | 1.88 ↓ lower | 1.91 ↑ higher |
| Electron affinity | 0.661 eV ↓ lower | 1.156 eV ↑ higher |
| Group | 9 | 10 |
| Electron configuration | [Ar]3d74s2 | [Ar]3d84s2 |
| Discovery year | 1735 | 1751 |