Thorium element properties

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Name: Thorium Symbol: Th
Group: Rare Earth, Actinides Atomic weight: 232.0381
Density @ 293 K: 11.7 g/cm3 Atomic volume: 19.9 cm3/mol
Group: Rare Earth, Actinides discovered: 1829


state (s, l, g): s
melting point: 2023.2 K boiling point: 5123 K
Heat of fusion: 16.10 kJ/mol Heat of vaporization: 514.40 kJ/mol


1st ionization energy: 587 kJ/mole
electronegativity: 1.3 2nd ionization energy: 1110 kJ/mole
electron affinity: kJ/mole 3rd ionization energy: 1930 kJ/mole
Specific heat: 0.12 J/gK heat atomization: 576 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,18,32,18,10,2 electron configuration: [Rn] 6d2 7s2
minimum oxidation number: 0 maximum oxidation number: 4
min. common oxidation no.: 0 max. common oxidation no.: 4

Appearance & Characteristics:

structure: fcc: face-centered cubic color: white
uses: gas mantles (ThO2) toxicity:
hardness: mohs characteristics: Radioactive


reaction with air: mild, w/ht ignites =>ThO2
reaction with 6M HCl: mild reaction with 6M HCl: mild
reaction with 15M HNO3: passivated reaction with 6M NaOH: none

Other Forms:

number of isotopes: 3 hydride(s): ThH2 Th4H15
oxide(s): ThO2 chloride(s): ThCl4


ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 179 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): pm ionic radius (3+ ion): pm


thermal conductivity: 54 J/m-sec-deg
electrical conductivity: 76.923 1/mohm-cm polarizability: 32.1 A^3


source: Monazite(phosphate),U extractn
rel. abund. solar system: -1.475 log abundance earth's crust: 1 log
cost, pure: $/100g cost, bulk: $/100g

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