Back to Periodic Table
90Th232.04 u

Thorium

actinide
Atomic Number
90
Atomic Mass
232.04 u
Period
7
Group
3

Quick Facts

PropertyValue
SymbolTh
Atomic Number90
Atomic Mass232.04 u
CategoryActinide
Period7
Group3
Blockf
Electron Configuration[Rn] 6d² 7s²

History and Discovery

Discovered by: Jöns Jacob Berzelius Year of Discovery: 1829 Location: Stockholm, Sweden

Etymology

Named after Thor, the Norse god of thunder.

Applications and Uses

  • Potential nuclear fuel (thorium reactors)
  • Historically: gas mantles (incandescent lighting)
  • Welding electrodes
  • High-quality lenses
  • Magnesium alloys

Nuclear Potential

Thorium could fuel nuclear reactors with less weapons-grade material production than uranium. India and China are researching thorium reactors.

Interesting Facts

  1. More abundant than uranium
  2. Named after the Norse god Thor
  3. Could power reactors for thousands of years
  4. Thoriated gas mantles were common until the 1990s
  5. Produces less nuclear waste than uranium