| ChemGlobe: Thorium: Electronic, thermal, and steric data along with an isotope table. |
| ChemicalElements.com: Thorium: Basic information, atomic structure, and isotopes. |
| EnvironmentalChemistry.com: Thorium: Atomic structure, chemical and physical properties, and table of nuclides. |
| It's Elemental: Thorium: Basic physical and historical information. |
| LANL: Thorium: Uses, properties, production, properties. |
| Lenntech: Thorium: Physical data, chemical properties, health and environmental effects. |
| Thorium: Data tables and historic information. |
| Thorium: An information source of thorium and thorium-related topics. |
| USGS Minerals Information: Thorium: Statistics and information on the worldwide supply, demand, and flow of the element (PDF format). |
| Visual Elements: Thorium: Image, general and physical information, and key isotopes. |
| WebElements: Thorium: Extensive information on history, uses, occurrence, compounds, and properties. |
| Wikipedia: Thorium: Properties of the element, including its history, applications, and characteristics. |
Classical
