• Class: AcTinides
• Period: 7
• IUPAC group: 3
• Traditional: IIIa

• Discovered in: 1828 by Berzelius
• Origin of name: Thor, Scandinavian god of war
• Historical or alternate name:

Monazite

Silvery metal. Tarnishes in air; reacts with water.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 0.064 ppm
• Sea water: 0.0007 ppm
• Metallic meteorite: 0.0286 ppm
• ConTinental crust: 3.5 ppm
• Solar photosphere: 0.2 log of abundance
• Oceanic crust: 0.22 ppm
• Solar system: 0.0335 relative to Si=1.0e6

   Hazards

Poison. Flammable. Radioactive. Carcinogen. Reacts violently with oxidants..

• Lower:
• Upper:0.01

Thorium Physical Properties

 Transitional Data

• State: Solid
• Density: 11.7 g/cm3

 Molar enthalpy

• Atomization: 598.65 kJ mol-1
• Fusion: 19.2 kJ mol-1
• Vaporization: 513.67 kJ mol-1

 Transition points

• MelTing point: 2023.0 K
• Boiling point: 5063.0 K
• Critical temperature: 14550.0 K

 Molar properties

• Atomic weight: 232.0381 g/mole
• Molar volume: 19.922 cm3 mol-1

 Crystal structure sequence

face-centered-cubic <1673 K < body-centered-cubic < melTing point

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 53.39
  • Heat Capacity 27.32

• State: gas
  • Enthalpy 598.3
  • Gibbs function 557.53
  • Entropy 190.15
  • Heat Capacity 20.79

 Miscellaneous physical

• Electrical resistivity: 13.0 µ-ohms/cm
• Debye temperature: 163.0 K
• Thermal conductivity: 54.0 W / m / K
• Coefficient of linear expansion: 11.1Coef. per K
• Mass magnetic susceptibility: 7.2e-9
• X-ray diffraction mass absorption coefficients:
• CuK: 327 (µ/p)/cm2 g-1
• MoK: 143 (µ/p)/cm2 g-1

Thorium Chemical Properties

 Chemical basics:

• Oxidation states: +3 +4
• Molecular wt: 232.0381 g/mole

 Radii

• Covalent: pm
• Atomic: 179.0 pm
• Van der Waals: pm

 Ions:

• ion: +3 pm 108.0
• ion: +4 pm 94.0

 Covalent bonds

 Effective nuclear charge

• Slater: 1.95
• Clementi:
• Froese-Fischer:

 Electronegativity

• Pauling: 1.3
• Allred-Rochow: 1.11

 Standard reactions

Thorium Nuclear Properties

• Known 12
• Listed 6

• Known 223 - 234
• Listed 227 - 234

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 18.6 days
  • Decay mode: alpha,
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 1.9 years
  • Decay mode: alpha,
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 5/2
• Radioisotopes:
  • Half-life: 73.4 centuries
  • Decay mode: alpha,
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 752.0 centuries
  • Decay mode: alpha,
  • Source:
• Notes

• % Occ.:Natural 100.0%
• Mossbauer NRA: 7.91
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 13.9 E9 years
  • Decay mode: alpha, S.F.
  • Source:
• Notes date

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 24.1 days
  • Decay mode: Beta-
  • Source:
• Notes

• Isotope Cross-section 7.4±0.1 barns

• Absolute sensitivity: 1H=1.0
• Relative sensitivity: 1H=1.0
• Receptivity: 13C=1.0
• Magnetogyric ratio: 0.40e7 rad / T / s
• Quadropole moment: 4.4e-28 m2
• Frequency: 1.5 MHz
• Reference:

Thorium Energy Properties

Electrons

• Ground state electron configuration: [Rn] 6d2 7s2
• Electron affinity: kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels