Th
Thorium
Atomic number: 90Mass: 232.038 uCategory: Actinide
About Thorium
Thorium is a weakly radioactive, lustrous, silvery-white metal. It was once used in gas mantles in camping lanterns. Thorium is explored as a safer nuclear fuel because it is more abundant than uranium and produces less long-lived waste.
Properties
Period
7
Group
N/A
Block
F
Category
Actinide
Electronegativity
1.30 (Pauling)
Ionization Energy
587 kJ/mol
Melting Point
2023 K (1750°C)
Boiling Point
5061 K (4788°C)
Density
11.7 g/cm³
Oxidation States
+4
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 6d² 7s²
[Rn] 6d² 7s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:32e⁻
Shell 5:18e⁻
Shell 6:10e⁻
Shell 7:2e⁻
Real-World Uses
Experimental nuclear fuel
Camping lantern mantles (old)
Magnesium alloys
Crucibles
Radiation shielding (experimental)
Fun Fact
Thorium could power the entire world's energy needs for thousands of years — it's 3× more abundant than uranium and produces far less radioactive waste!