U.S. flag

An official website of the United States government


Send to:

Choose Destination


A radioactive element of the actinide series of metals. It has an atomic symbol Th, atomic number 90, and atomic weight 232.04. It is used as fuel in nuclear reactors to produce fissionable uranium isotopes. Because of its radioopacity, various thorium compounds are used to facilitate visualization in roentgenography.

PubMed search builder options


Tree Number(s): D01., D01.268.556.850, D01.496.749.305.100.900, D01.552.020.889, D01.552.544.850

MeSH Unique ID: D013910

Registry Number: 60YU5MIG9W

Supplemental Content

Loading ...
Support Center