Assertion: thorium's isotope | /r/HasProperty | stable
Facets:
value: relatively
type: DEGREE
value: for all purposes
type: PURPOSE
value: practically
type: DEGREE
Source sentences:
text: All but two elements up to bismuth (element 83) have an isotope that is practically stable for all purposes ("classically stable"), with the exceptions being technetium and promethium (elements 43 and 61).
text: One isotope, 232Th, is relatively stable, with a half-life of 1.405×1010 years, considerably longer than the age of the Earth, and even slightly longer than the generally accepted age of the universe.
text: All these isotopes are stable and are also present in nature as primordial nuclides, but their excess amounts in comparison with lead-204 (which has only a primordial origin) can be used in the technique of uranium-lead dating to date rocks.