Thorium

Metal

Symbol: Th
Atomic number: 90
Atomic mass: 232.0381
Group: Actinide
CAS-number: 7440-29-1

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Electronic data

Shells: 2, 8, 18, 32, 18, 10, 2
Orbitals: [Rn] 6d² 7s²
Electronegativity: --, 1.1
1. Ionization potential: 6.08 eV
2. Ionization potential: 11.504 eV
3. Ionization potential: 20.003 eV
Oxidation states: 4
Electrical conductivity: 0.0653 10^6

Thermal data

Melting point: 1750 °C
Boiling point: 4000 °C
Specific heat: 0.12 J/gK
Heat of fusion: 16.10 kJ/mol
Heat of vaporization: 514.40 kJ/mol
Thermal conductivity: 0.540 W/cmK

Steric data

Atomic radius: -- Å
Ionic radius: 1.05 Å (+4)
Covalent radius: 1.65 Å
Atomic volume: 19.9 cm³/mol
Density (293 K): 11.7 g/cm³
Crystal structure: cubic face centered

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
²²⁶Th	0	226.025	0	30.6m	α	View
²²⁷Th	0	227.028	3/2	18.72d	α	View
²²⁸Th	0	228.029	0	1.913y	α	View
²²⁹Th	0	229.032	5/2	7.34E03y	α	View
²³⁰Th	0	230.033	0	7.54E04y	α	View
²³¹Th	0	231	5/2	1.063d	β-	View
²³²Th	100	232.038	0	1.40E10y	α	View
²³³Th	0	233	1/2	22.3m	β-	View
²³⁴Th	0	234	0	24.1d	β-	View

Name origin:	Named for Thor, Norse god of thunder.
Description:	Heavy, gray, soft, malleable, ductile, radioactive metal.
Discovered by:	Jöns Berzelius
Year:	1828
Place:	Sweden
Sources:	Found in various minerals like monazite and thorite.
Use(s):	Used in making strong alloys. Also in ultraviolet photoelectric cells. It is a common ingredient in high-quality lenses. Bombarded with neutrons make uranium-233, a nuclear fuel.

Thorium

Physical data

Electronic data

Thermal data

Steric data

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