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Noun1.thorium-228 - radioactive isotope of thorium with mass number 228
atomic number 90, thorium, Th - 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
References in periodicals archive ?
228]Th gives rise to a chronometer that has the potential to determine the time when fluids were extracted from the Marcellus Shale (for more information, see Supplemental Material, "Expanded methods, Thorium-228 ingrowth").