Cobalt

Transition metal · 58.93319 u · group 9, period 4

Cobalt · Co

Atomic number27

SymbolCo

CategoryTransition metal

Standard stateSolid

Group · Period · Block9 · 4 · d

Electron configuration[Ar]4s2 3d7

Atomic mass58.93319 u

Atomic radius192 pm

Protons / Neutrons / Electrons27 / 32 / 27

Shells (e⁻ per shell)2, 8, 15, 2

Electronegativity (Pauling)1.88

Ionization energy7.881 eV

Electron affinity0.661 eV

Oxidation states+3, +2

Melting point1.77e+3 K · 1.49e+3 °C

Boiling point3.20e+3 K · 2.93e+3 °C

Density8.86 g/cm³

Year discovered1735

CPK color

#F090A0

State at room temp (25 °C)

solid

Position