27Solid
Co 58.933 Atomic mass · uTransition metals
Cobalt
Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Discovery Ancient (Georg Brandt)
K2L8M15N2
Physical properties
Values for the element in its standard state.
- Density
- 8.9g/cm³
- Melting point
- 1,768K
- Boiling point
- 3,200K
- Atomic radius
- 126pm
- Bonding type
- Metallic
- Molar heat
- 24.81J/(mol·K)
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 6 electrons; 3d, 7 electrons; 4s, 2 electrons;
[Ar] represents 18 core electrons. The full view shows them explicitly.
27 electrons Orbital order preserved from source
- Electronegativity
- 1.88Pauling scale
- First ionization energy
- 760kJ/mol
- Electron affinity
- 64kJ/mol
- Van der Waals radius
- Not available
Co CobaltAtomic number 27
760kJ/mol
Atomic numberGaps indicate unavailable data
About cobalt
- Appearance
- Hard lustrous gray metal
- Discovery
- Ancient (Georg Brandt)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.