Cobalt (Co)
Cobaltum
Cobalt (Co) is a transition metal in period 4, group 9. Its relative atomic mass is 58.933 and the molar mass of the atom is 58.933 g/mol.
Atomic number 27
Atomic mass 58.933
Molar mass 58.933 g/mol
Category Transition metal Solid
Properties of cobalt
| Atomic number | 27 |
|---|---|
| Symbol | Co |
| Latin name | Cobaltum |
| Relative atomic mass | 58.933 |
| Molar mass | 58.933 g/mol |
| Group, period, block | 9, 4, d |
| Category | Transition metal |
| State at 20 °C | Solid |
| Electron configuration | [Ar] 3d⁷ 4s² |
| Electronegativity (Pauling) | 1.88 |
| Atomic radius | 135 pm |
Electron configuration of cobalt
Electrons per shell
K2L8M15N2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷ 4s²
Noble-gas notation
27 protons · 27 electrons[Ar] 3d⁷ 4s²
Formula and compounds of cobalt
Simple substanceCocobaltMolar mass of Co: 58.933 g/mol
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Frequently asked questions
The relative atomic mass of cobalt is 58.933, so the molar mass of the atom is 58.933 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷ 4s². Noble-gas notation: [Ar] 3d⁷ 4s².