Chromium (Cr) - Element 24 | Properties & Electron Configuration

What is Chromium?

Chromium (Cr) is element 24, a transition metal in period 4, group 6. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹.

Atomic Number24
SymbolCr
Atomic Mass51.996 u
CategoryTransition Metal
Period4
Group6
Blockd
Electron Configuration1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
Short Config[Ar] 3d⁵ 4s¹
Electronegativity1.66
Atomic Radius140 pm
Ionization Energy653 kJ/mol
Electron Affinity64 kJ/mol
Phase (STP)Solid

Electron Configuration

The full electron configuration of Chromium is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹. In noble gas shorthand, this is written as [Ar] 3d⁵ 4s¹.

Chromium is a d-block element in group 6, period 4.

Periodic Trends

Electronegativity: Chromium has a Pauling electronegativity of 1.66. Within group 6, electronegativity generally decreases down the group.

Atomic Radius: 140 pm. Across period 4, atomic radius generally decreases left to right as nuclear charge increases.

Ionization Energy: 653 kJ/mol. Ionization energy generally increases across a period and decreases down a group.

View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.

Explore Chromium on the Interactive Periodic Table

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