Assertion: thorium's isotope | /r/HasProperty | unstable
Facets:
value: with the seven naturally occurring ones
type: OTHER
Source sentences:
text: All isotopes of thorium are unstable.
text: Uranium is weakly radioactive because all isotopes of uranium are unstable; the half-lives of its naturally occurring isotopes range between 159,200 years and 4.5 billion years.
text: Thorium is weakly radioactive : all its known isotopes are unstable , with the seven naturally occurring ones (thorium-227, 228, 229, 230, 231, 232, and 234).