90 Th 232.04
Thorium
Actinide
Thorium (Th) is a chemical element with atomic number 90, classified as a actinide. At room temperature it is a solid. It was discovered in 1829 by Jöns Jacob Berzelius.
Properties
- Atomic number
- 90
- Atomic mass
- 232.04 u
- Category
- Actinide
- Group
- 0
- Period
- 7
- Block
- f-block
- Electron configuration
- [Rn] 6d² 7s²
- Phase at STP
- Solid
- Density
- 11.72 g/cm³
- Melting point
- 2115 K (1841.8 °C)
- Boiling point
- 5061 K (4787.9 °C)
- Electronegativity
- 1.3
- Atomic radius
- 237 pm
- Ionization energy
- 6.307 eV
- Discovery
- 1829 · Jöns Jacob Berzelius
Common uses
Nuclear reactors, mantles for gas lamps, alloys
Did you know?
Potential nuclear fuel that's more abundant than uranium.