Cerium

Analytical testing dots

Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a silvery metal, belonging to the lanthanide group. It resembles iron in color and luster, but is soft, and both malleable and ductile. Cerium has the longest liquid range of any non-radioactive element: 2648 °C (795 °C to 3443 °C) or 4766 °F (1463 °F to 6229 °F). (Thorium has a longer liquid range.)

Although cerium belongs to chemical elements group called rare earth metals, it is in fact more common than lead. Cerium is available in relatively large quantities (68 ppm in Earth’s crust). It is used in some rare-earth alloys.

 

General
Name, Symbol, Number cerium, Ce, 58
Chemical series lanthanides
Group, Period, Block n/a, 6, f
Appearance silvery white
Standard atomic weight 140.116(1) g·mol-1
Electrons per shell 2, 8, 18, 19, 9, 2
Physical properties
Phase solid
Density (near r.t.) 6.770 g·cm−3
Liquid density at m.p. 6.55 g·cm−3
Melting point 1068K
(795°C, 1463°F)
Boiling point 3716K
(3443°C, 6229°F)
Heat of fusion 5.46 kJ·mol-1
Heat of vaporization 398 kJ·mol-1
Heat capacity (25°C) 26.94 J·mol-1·K-1
Vapor pressure
P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 1992 2194 2442 2754 3159 3705
Atomic properties
Crystal structure cubic face centered
Oxidation states 3, 4
(mildly basic oxide)
Electronegativity 1.12 (Pauling scale)
Ionization energies
(more)		 1st: 534.4 kJ·mol-1
2nd: 1050 kJ·mol-1
3rd: 1949 kJ·mol-1
Atomic radius 185 pm
Miscellaneous
Magnetic ordering no data
Electrical resistivity (r.t.) (β, poly) 828 nΩ·m
Thermal conductivity (300K) 11.3 W·m-1·K-1
Thermal expansion (r.t.) (γ, poly)
6.3 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2100 m/s
Young's modulus (γ form) 33.6 GPa
Shear modulus (γ form) 13.5 GPa
Bulk modulus (γ form) 21.5 GPa
Poisson ratio (γ form) 0.24
Mohs hardness 2.5
Vickers hardness 270 MPa
Brinell hardness 412 MPa
CAS registry number 7440-45-1

 

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