Assertion: protactinium's isotope | /r/HasProperty | reached after a series of decays
Facets:
value: often
type: TEMPORAL
Source sentences:
text: Unstable isotopes decay to their daughter products (which may sometimes be even more unstable) at a given rate; eventually, often after a series of decays, a stable isotope is reached: there are about 200 stable isotopes in the universe.