radioisotope

Meanings

1. 1
   noun

   a radioactive isotope of an element, whose unstable nuclei decay and emit radiation

   The laboratory used a short-lived radioisotope to trace how the compound moved through the cells.

A twentieth-century scientific compound of radio-, here meaning radioactive, + isotope. Isotope was coined from Greek isos ("equal") + topos ("place") because isotopes occupy the same place in the periodic table despite differing in atomic mass.

Topics