Technical data for Chromium

Overview
NameChromium
SymbolCr
Atomic Number24
Atomic Weight51.9961
Density7.14 g/cm3
Melting Point1907 °C
Boiling Point2671 °C

Thermal properties
PhaseSolid
Melting Point1907 °C
Boiling Point2671 °C
Absolute Melting Point2180 K
Absolute Boiling Point2944 K
Heat of Fusion20.5 kJ/mol
Heat of Vaporization339 kJ/mol
Heat of CombustionN/A
Specific Heat448 J/(kg K)[note]
Neel Point393 K
Thermal Conductivity94 W/(m K)
Thermal Expansion4.9×10-6 K-1

Bulk physical properties
Density7.14 g/cm3
Density (Liquid)6.3 g/cm3
Molar Volume7.2824×10-6
Brinell Hardness1120 MPa
Mohs Hardness8.5 MPa
Vickers Hardness1060 MPa
Bulk Modulus160 GPa
Shear Modulus115 GPa
Young Modulus279 GPa
Poisson Ratio0.21
Refractive IndexN/A
Speed of Sound5940 m/s
Thermal Conductivity94 W/(m K)
Thermal Expansion4.9×10-6 K-1

Reactivity
Valence6
Electronegativity1.66
ElectronAffinity64.3 kJ/mol
Ionization Energies
652.9, 1590.6, 2987, 4743, 6702, 8744.9, 15455, 17820, 20190, 23580, 26130, 28750, 34230, 37066, 97510, 1.058×105, 1.143×105, 1.253×105, 1.347×105, 1.443×105, 1.577×105 kJ/mol

Health and Safety
Autoignition Point400 °C
FlashpointN/A

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blockd
Group6
Period4
Electron Configuration[Ar]3d54s1
ColorSilver
Discovery
1797 in France
Gas phaseN/A
CAS NumberCAS7440-47-3

Electrical properties
Electrical TypeConductor
Electrical Conductivity7.9×106 S/m
Resistivity1.3×10-7 m Ω
Superconducting PointN/A

Magnetic properties
Magnetic TypeAntiferromagnetic
Curie PointN/A
Mass Magnetic Susceptibility4.45×10-8
Molar Magnetic Susceptibility2.314×10-9
Volume Magnetic Susceptibility0.0003177

Abundances
% in Universe0.0015%
% in Sun0.002%
% in Meteorites0.3%
% in Earth's Crust0.014%
% in Oceans6×10-8%
% in Humans3×10-6%

Atomic dimensions and structure
Atomic Radius166 pm
Covalent Radius127 pm
Van der Waals RadiusN/A
Crystal StructureBody Centered Cubic
Lattice Angles
π/2, π/2, π/2
Lattice Constants
291, 291, 291 pm
Space Group NameIm_ 3m
Space Group Number229

Nuclear Properties
Half-LifeStable
LifetimeStable
Stable Isotopes
50Cr, 52Cr, 53Cr, 54Cr
Isotopic Abundances
50Cr4.345%
52Cr83.789%
53Cr9.501%
54Cr2.365%

Notes on the properties of Chromium:
Specific Heat: Value given for solid phase.