thorite
— Noun
– English
~ a radioactive mineral consisting of thorium silicate; it is a source of thorium that is found in coarse granite
thorium
— Noun
– English
~ a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
thorium-228
— Noun
– English
~ radioactive isotope of thorium with mass number 228