Cobalt |
| Symbol | Co |
|---|---|
| Latin name | Cobaltum |
| Atomic number | 27 |
| Period | 4 |
| Element category | Transition elements |
| Relative atomic mass | 58.93320 |
| Group | VIII.B |
| Electronegativity | 1.8 |
| Oxidation numbers | 2, 3 |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d7 4s2 |
| Density [g/cm3] | 8.9 |
| State | Solid |
| Melting point [°C] | 1494 |
| Boiling point [°C] | 2900 |
| Atomic radius [pm] | 152 |
| Covalent radius [pm] | 126 |
| Thermal conductivity [W m-1K-1] | 100 |
| Heat capacity [J K-1g-1] | 0.421 |
| Discovery | 1735 |
| Hardness [Mohs scale] | 5.5 |
| Vickers hardness [MPa] | 1043 |
| Brinell hardness [MPa] | 700 |
| Young's modulus [GPa] | 209 |
| Electrical conductivity [S m-1] | 1.7 · 107 |
| Shear modulus [GPa] | 75 |
| 1.st ionization energy [eV] | 7.881 |
| 2.nd ionization energy [eV] | 17.06 |
| 3.rd ionization energy [eV] | 33.5 |
| Stable isotopes | 1 |
| Unstable isotopes | 13 |