Assertion: erbium's isotope | /r/HasProperty | unstable
Facets:
value: relatively
type: DEGREE
Source sentences:
text: All the radioactive isotopes of erbium are relatively unstable: their half-lives range from 1 second (erbium-145) to 9.4 days (erbium-169).
text: In addition, ten radioactive isotopes are also known; these isotopes are unstable and break down into other isotopes giving out radiation in the process.