27Co58.933
Cobalt (Co)
Element 27 Ā· Transition metal
Cobalt (Co) is a chemical element with atomic number 27. It is classified as a transition metal in period 4, group 9 of the periodic table (the d-block). Its standard atomic weight is 58.933 u and its ground-state electron configuration is [Ar] 3dā· 4sĀ².
Cobalt facts
| Atomic number (Z) | 27 |
|---|---|
| Symbol | Co |
| Standard atomic weight | 58.933 u |
| Category | Transition metal |
| Group | 9 |
| Period | 4 |
| Block | d-block |
| Electron configuration | [Ar] 3dā· 4sĀ² |
| Electronegativity (Pauling) | 1.88 |
| State at 20 Ā°C | Solid |
| Protons / electrons | 27 / 27 |
| Neutrons (most common isotope, approx.) | 32 |
| Molar mass | 58.933 g/mol |