• Class: Lanthinides
• Period: 6
• IUPAC group: 3
• Traditional: IIIa

• Discovered in: 1803 by Klaproth, Berzelius, Hisinger
• Origin of name: The asteroid Ceres
• Historical or alternate name:

Allanite or orthite, monazite, bastnasite, cerite & samarskite

Grey metal. Tarnishes in air; reacts easily with water. Dissolves in acids; ignites when heated.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 1.436 ppm
• Sea water: 0.0004 ppm
• Metallic meteorite: 0.619 ppm
• ConTinental crust: 33.0 ppm
• Solar photosphere: 1.55 log of abundance
• Oceanic crust: 11.5 ppm
• Solar system: 1.16 relative to Si=1.0e6

   Hazards

Metal ignites and burns readily. Toxic by inhalation. Strong reductant..

• Lower:0.01
• Upper:1.0

Cerium Physical Properties

 Transitional Data

• State: Solid
• Density: 6.657 g/cm3

 Molar enthalpy

• Atomization: 423.4 kJ mol-1
• Fusion: 8.87 kJ mol-1
• Vaporization: 398 kJ mol-1

 Transition points

• MelTing point: 1072.0 K
• Boiling point: 3699.0 K
• Critical temperature: 10400.0 K

 Molar properties

• Atomic weight: 140.115 g/mole
• Molar volume: 20.83 cm3 mol-1

 Crystal structure sequence

face-centered-cubic <95 K < double-hex-close-packed < 263 K < face-centered-cubic < 1003 K < body-centered-cubic < melTing point

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 72.0
  • Heat Capacity 26.94

• State: gas
  • Enthalpy 423
  • Gibbs function 383
  • Entropy 191.776
  • Heat Capacity 23.075

 Miscellaneous physical

• Electrical resistivity: 75.0 µ-ohms/cm
• Debye temperature: K
• Thermal conductivity: 11.4 W / m / K
• Coefficient of linear expansion: 5.3Coef. per K
• Mass magnetic susceptibility: 2.17e-7
• X-ray diffraction mass absorption coefficients:
• CuK: 352 (µ/p)/cm2 g-1
• MoK: 48.2 (µ/p)/cm2 g-1

Cerium Chemical Properties

 Chemical basics:

• Oxidation states: +3 +4
• Molecular wt: 140.115 g/mole

 Radii

• Covalent: 165 pm
• Atomic: 181.8 pm
• Van der Waals: pm

 Ions:

• ion: +3 pm 101.0
• ion: +4 pm 87.0

 Covalent bonds

 Effective nuclear charge

• Slater: 2.85
• Clementi: 10.80
• Froese-Fischer: 10.57

 Electronegativity

• Pauling:
• Allred-Rochow: 1.06

 Standard reactions

Cerium Nuclear Properties

• Known 19
• Listed 7

• Known 132 - 148
• Listed 136 - 144

• % Occ.:Natural 0.19%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 0.25%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 138.0 days
  • Decay mode: E.C.,
  • Source: reactor
• Notes

• % Occ.:Natural 88.48%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 32.5 days
  • Decay mode: Beta-
  • Source: reactor
• Notes

• % Occ.:Natural 11.08%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 285.0 days
  • Decay mode: Beta-
  • Source: reactor
• Notes

• Isotope Cross-section 0.73±0.08 barns

Cerium Energy Properties

Electrons

• Ground state electron configuration: [Xe] 4f1 5d1 6s2
• Electron affinity: 50 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels