Co
Cobalt Symbol (Co)
Cobalt is element 27 of the periodic table. Copy its symbol Co and see its atomic weight, electron configuration and common compounds.
What does Co mean?
Co is the chemical symbol for cobalt, element number 27 in the periodic table. Cobalt is a transition metal in group 9, period 4. It is used in lithium-ion battery cathodes and blue pigments; vitamin B12 contains cobalt.
Codes and properties
| Chemical symbol | Co |
|---|---|
| Atomic number (Z) | 27 |
| Atomic weight (PubChem) | 58.93319 |
| Group / period | 9 / 4 |
| Element category | transition metal |
| Electron configuration | [Ar]4s² 3d⁷ |
| State at 20 °C | Solid |
| Oxidation states | +3, +2 |
| Electronegativity (Pauling) | 1.88 |
| Melting point | 1768 K (1494.85 °C) |
| Boiling point | 3200 K (2926.85 °C) |
| Density | 8.86 g/cm³ |
| Discovered | 1735 |
| Common compounds | CoCl₂, Co₃O₄ |
How to type Co
- Plain text: type
Co— element symbols are ordinary Latin letters, with the first letter capitalised and the second lowercase. - Subscripts in formulas: use Unicode subscript digits (₀₁₂₃₄₅₆₇₈₉) for formulas such as CoCl₂ — copy them from the chemistry keyboard.
- LaTeX: write
\mathrm{Co}in math mode, or use the mhchem package:\ce{Co}. - HTML:
Co; for subscripts use<sub>, e.g.H<sub>2</sub>O.
Frequently asked questions
What is the chemical symbol for cobalt?
The chemical symbol for cobalt is Co.
What is the atomic number of cobalt?
Cobalt has atomic number 27, meaning each atom has 27 protons.
What is the electron configuration of cobalt?
The ground-state electron configuration of cobalt is [Ar]4s² 3d⁷.
Related symbols
Keep exploring
Reference: Cobalt on PubChem (NIH)