Chromium

Transition metal · 51.996 u · group 6, period 4

Chromium · Cr

Atomic number24

SymbolCr

CategoryTransition metal

Standard stateSolid

Group · Period · Block6 · 4 · d

Electron configuration[Ar]3d5 4s1

Atomic mass51.996 u

Atomic radius189 pm

Protons / Neutrons / Electrons24 / 28 / 24

Shells (e⁻ per shell)2, 8, 13, 1

Electronegativity (Pauling)1.66

Ionization energy6.767 eV

Electron affinity0.666 eV

Oxidation states+6, +3, +2

Melting point2.18e+3 K · 1.91e+3 °C

Boiling point2.94e+3 K · 2.67e+3 °C

Density7.15 g/cm³

Year discovered1797

CPK color

#8A99C7

State at room temp (25 °C)

solid

Position

1 in library