thorium
A chemical element (symbol ) with atomic number 90. A weakly radioactive, malleable, moderately hard silvery metal that tarnishes black when exposed to air.
Related words
- althupite
- dithorium
- mesothorium
- nonthorium
- organothorium
- radiothorium
- thoriferous
- trithorium
- eka-thorium
- thorate
- thoria
- thorian
Where this comes from
This definition is adapted from “thorium” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.