Cr
Chromium
Atomic number: 24Mass: 51.996 uCategory: Transition Metal
About Chromium
Chromium is a steely-grey lustrous metal. It is the main component in stainless steel, giving it corrosion resistance. Chromium compounds are brilliantly coloured and used as pigments.
Properties
Period
4
Group
6
Block
D
Category
Transition Metal
Electronegativity
1.66 (Pauling)
Ionization Energy
652.9 kJ/mol
Melting Point
2180 K (1907°C)
Boiling Point
2944 K (2671°C)
Density
7.15 g/cm³
Oxidation States
+2, +3, +6
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
[Ar] 3d⁵ 4s¹
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:13e⁻
Shell 4:1e⁻
Real-World Uses
Stainless steel
Chrome plating
Pigments
Leather tanning
Catalysts
Fun Fact
Rubies get their red colour from trace amounts of chromium! Emeralds also contain chromium but appear green instead.