90 Th Thorium 232.04
Actinide
Thorium 钍
[Rn] 6d² 7s²
- Period 7
- Group —
- Block f
- Solid
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 6d² 7s²
Orbital diagram (valence)
- Electrons per shell
- 2, 8, 18, 32, 18, 10, 2
- Unpaired electrons
- 2
- Zeff (Slater)
- 3.15
Properties
- Atomic weight
- 232.04
- Electronegativity (Pauling)
- 1.3
- First ionization energy
- 586.6 kJ/mol
- Electron affinity
- no data
- Covalent radius
- 206 pm
- van der Waals radius
- 237 pm
- Melting point
- 2023 K
- Boiling point
- 5061 K
- Density
- 11.72 g/cm³
- Melting / boiling point
- 1749.8 °C / 4787.9 °C
- Common oxidation states
- +4
- Discovered
- 1828
Thorium in the course
The lessons that discuss this element most (ranked by mentions).
Periodic trend
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).