Thorium (Th) — Element 90: Properties & Data | Aladdin Scientific
Thorium(Th) — Element 90
Thorium (Th) is a actinide with atomic number 90 and atomic mass 232.038. It has melting point 2023 K (1750 °C), boiling point 5061 K (4788 °C), density 11.72 g/cm³. It sits in period 7 of the periodic table and was discovered in 1828.
Key facts
| Atomic mass | 232.0380 u |
|---|---|
| Electron configuration | [Rn]7s2 6d2 |
| Oxidation states | +4 |
| Electronegativity (Pauling) | 1.3 |
| Atomic radius (van der Waals) | 237 pm |
| Ionization energy | 6.08 eV |
| Melting point | 2023 K |
| Boiling point | 5061 K |
| Density | 11.72 g/cm³ |
| Standard state | Solid |
| Year discovered | 1828 |
Frequently asked questions
What is the electron configuration of thorium?
The ground-state electron configuration of thorium is [Rn]7s2 6d2.
What group and period is thorium in?
Thorium (Th) is in period 7 (actinide series) of the periodic table, classified as a actinide.
What is the melting point of thorium?
Thorium melts at 2023 K (1750 °C).
What is the standard state of thorium?
Thorium is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .