90Th

Thorium

Actinide

Thorium (Th) is element 90, an actinide, in period 7 of the periodic table. Its standard atomic weight is 232.038, it melts at 1750 °C and boils at 4788 °C. Discovered by Jons Jacob Berzelius, 1829.

Atomic Number90

SymbolTh

NameThorium

Atomic Weight232.038 u

CategoryActinide

Period7

Melting Point1750 °C

Boiling Point4788 °C

Density11.72 g/cm³

Electron Config[Rn] 6d2 7s2

Discovered ByJons Jacob Berzelius, 1829

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