Cerium Facts - Ce or Atomic Number 58

Cerium (Ce) is atomic number 58 on the periodic table. Like other lanthanides or rare earth elements, cerium is a soft, silver-colored metal. It's the most abundant of the rare earth elements.

Cerium Basic Facts

Element Name: Cerium

Atomic Number: 58

Symbol: Ce

Atomic Weight: 140.115

Element Classification: Rare Earth Element (Lanthanide Series)

Discovered By: W. von Hisinger, J. Berzelius, M. Klaproth

Discovery Date: 1803 (Sweden/Germany)

Name Origin: Named after the asteroid Ceres, discovered two years before the element.

Cerium Physical Data

Density (g/cc) near r.t.: 6.757

Melting Point (°K): 1072

Boiling Point (°K): 3699

Appearance: Malleable, ductile, iron-gray metal

Atomic Radius (pm): 181

Atomic Volume (cc/mol): 21.0

Covalent Radius (pm): 165

Ionic Radius: 92 (+4e) 103.4 (+3e)

Specific Heat (@20°C J/g mol): 0.205

Fusion Heat (kJ/mol): 5.2

Evaporation Heat (kJ/mol): 398

Pauling Negativity Number: 1.12

First Ionizing Energy (kJ/mol): 540.1

Oxidation States: 4, 3

Electronic Configuration: [Xe] 4f1 5d1 6s2

Lattice Structure: Face-Centered Cubic (FCC)

Lattice Constant (Å): 5.160

Electrons per Shell: 2, 8, 18, 19, 9, 2

Phase: Solid

Liquid Density at m.p.: 6.55 g·cm−3

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

Electronegativity: 1.12 (Pauling scale)

Atomic Radius: 185 pm

Electrical Resistivity (r.t.): (β, poly) 828 nΩ·m

Thermal Conductivity (300 K): 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

Sources: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952)

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