Nuclides
About the app ↗
Chemical element · Atomic number 24
Chromium (Cr)
Transition metals · Period 4 · Solid
Element identity
- Atomic number (Z)
- 24
- Symbol
- Cr
- Atomic weight / isotope mass number
- 51.9961(6)
- Category
- Transition metals
- Physical state (reference)
- Solid
- Period
- 4
- Group (reference)
- 6
- Block
- d
Physical properties
- Appearance
- Silvery metallic
- Density
- 7.19 g·cm⁻³
- Melting point
- 2180 K / 1907 °C / 3465 °F
- Boiling point
- 2944 K / 2671 °C / 4840 °F
- Sublimation point
- Not available
Atomic and material properties
- Electron configuration
- [Ar] 3d⁵ 4s¹
- Electrons per shell
- K2 L8 M13 N1
- Oxidation states
- 6, 5, 4, 3, 2, 1, −1, −2, −4
- Electronegativity (Pauling)
- 1.66
- Atomic radius
- 166 pm
- Covalent radius
- 139±5 pm
- Molar ionization energies
- 1st: 652.9 kJ·mol⁻¹ 2nd: 1590.6 kJ·mol⁻¹ 3rd: 2987 kJ·mol⁻¹ 4th: 4743 kJ·mol⁻¹ 5th: 6702 kJ·mol⁻¹ 6th: 8744.9 kJ·mol⁻¹ 7th: 15,455 kJ·mol⁻¹ 8th: 17,820 kJ·mol⁻¹ 9th: 20,190 kJ·mol⁻¹ 10th: 23,580 kJ·mol⁻¹ 11th: 26,130 kJ·mol⁻¹ 12th: 28,750 kJ·mol⁻¹ 13th: 34,230 kJ·mol⁻¹ 14th: 37,066 kJ·mol⁻¹ 15th: 97,510 kJ·mol⁻¹ 16th: 105,800 kJ·mol⁻¹ 17th: 114,300 kJ·mol⁻¹ 18th: 125,300 kJ·mol⁻¹ 19th: 134,700 kJ·mol⁻¹ 20th: 144,300 kJ·mol⁻¹ 21st: 157,700 kJ·mol⁻¹ 22nd: 166,090 kJ·mol⁻¹ 23rd: 721,870 kJ·mol⁻¹ 24th: 761,733 kJ·mol⁻¹
- Thermal conductivity
- 93.9 W·m⁻¹·K⁻¹
- Molar heat capacity
- 23.35 J·mol⁻¹·K⁻¹
- Crystal structure
- Body-centered cubic
- CAS number
- 7440-47-3
Property source: Wikipedia — Chromium, adapted from the Nuclides App snapshot. Quoted conditions and qualifiers are retained.
Sources and interpretation
Snapshot exported 24 October 2026 from the element assets used by Nuclides. Properties are a reference compilation, not a new evaluation. Missing values are shown as “Not available”. Density and phase depend on temperature, pressure and allotrope; retained conditions are part of the quoted property.
Atomic weight is dimensionless. Parentheses give uncertainty in the last quoted digits. A single integer in square brackets is an isotope mass number, not a standard atomic weight. The snapshot can differ from current evaluations; consult CIAAW standard atomic weights and the IUPAC periodic table for current values and conventions.
Element properties in the App snapshot are adapted from Wikipedia. Each element page links to its source article; text adaptations are available under CC BY-SA 4.0. No third-party images are included.
Go from elements to nuclear data
Keep Nuclides on your phone.
Explore connected element and nuclide references, decay chains and calculators in the app. See each store for pricing and in-app purchases.
