90 Th

Actinide

Thorium

Potential nuclear fuel.

See it in the interactive periodic table

Properties of Thorium

Atomic number (Z)
90
Symbol
Th
Atomic mass
232.04 g/mol
Category
Actinide
Group
3
Period
7
Electron configuration
[Rn] 6d² 7s²
Electronegativity (Pauling)
1.3
Atomic radius
180 pm
First ionization energy
587 kJ/mol
Melting point
2115 K (1841.8 °C)
Boiling point
5061 K (4787.9 °C)
Density
11.72 g/cm³
Phase at 25 °C
Solid
Discovered
Discovered in 1829
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