Periodic table of the elements
ActiniumThoriumProtactinium
90
Th
Thorium
232.0381
2
8
18
32
18
10
2
90
Th
Thorium
232.0381
2
8
18
32
18
10
2
General
NameThorium
SymbolTh
Number90
Chemical seriesActinides
Group / Period0 / 7
Blockf-block
CAS registry number7440-29-1

Thorium is a radioactive element

Physical properties
Statesolid
Density11.724 g/cm3
Melting point2115 K (1842 °C, 3348 °F)
Boiling point5061 K (4788 °C, 8650 °F)
Critical point

Atomic properties
Atomic Weight232.0381 g/mol
Crystal structurecubic face centered
Electronegativity1.30
Atomic radius180 pm
Atomic radius (calculated)
Electron configuration[Rn] 6d2 7s2
Electrons per shell2, 8, 18, 32, 18, 10, 2
Number of protons90
Number of neutrons142

Other languages
SpanishTorio
PortugueseTório
FrenchThorium
GermanThorium
ItalianTorio
RussianТорий
PolishTor
Chinese
Arabicثوريوم
TurkishToryum
DutchThorium


Periodic table of the elements
ActiniumThoriumProtactinium