mesothorium


Also found in: Dictionary, Wikipedia.

mes·o·tho·ri·um

(mez'ō-thōr'ē-ŭm),
The first two disintegration products of thorium; mesothorium 1 is 228Ra, a beta emitter with a half-life of 6.7 years, decaying into mesothorium 2, which is 228Ac, a beta emitter with a half-life of 6.13 hr, which disintegrates to radiothorium (228Th).