Assertion: uranium's isotope | /r/HasAspect | half-lives
Facets:
Source sentences:
text: These isotopes nevertheless still have half-lives too short to be primordial radionuclides and only exist in nature from these decay chains.
text: Each isotope has its own half-life, which is the time it takes for half of the atoms in a sample of the isotope to decay and the activity of the sample to be proportionately reduced.