Thorium (Th) is a chemical element belonging to the Actinide series (inner transition metal), with atomic number 90 and atomic mass 232.0380 u.
Identity
- Name: Thorium
- Symbol: Th
- Atomic number: 90
- Atomic mass: 232.0380 u
Position in the periodic table
- Series: Actinide
- Period: 7
- Block: f
Physico-chemical properties
- Standard state: Solid
- Melting point: 1750°C
- Density: 11.7 g/cm³
- Electron configuration: [Rn] 6d² 7s²
Scientific description
Thorium belongs to the actinide series, is naturally radioactive, and has a standard atomic mass of 232.0380 u.