24CrChromium51.99616[Ar] 3d⁵ 4s¹
transition metal
Chromium
Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
Electrons by shell
Electron configuration
3d5
4s1
18 is the [Ar] core total across three shells.
At a glance
- Atomic number
- 24
- Atomic mass
- 51.99616 u
- Phase
- Solid
- Density
- 7.19 g/cm³
- Melting point
- 2,180 K
- Boiling point
- 2,944 K
- First ionization energy
- 652.9 kJ/mol
- Electronegativity
- 1.66
- Electron affinity
- 65.21 kJ/mol
- Molar heat capacity
- 23.35 J/(mol·K)
- Period
- 4
- Appearance
- silvery metallic
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.