90
Th
Thorium
Actinide period 7 f-block discovered: 1828
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 90
- Atomic mass
- 232.038 a.m.u.
- Electron configuration
- [Rn]7s2 6d2
- Electronegativity
- 1.3 on the Pauling scale
- Atomic radius
- 237 pm
- Ionization energy
- 6.08 eV
- Oxidation states
- +4
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 2023 K (1 749,85 °C)
- Boiling point
- 5061 K (4 787,85 °C)
- Density
- 11.72 g/cm³