Assertion: erbium's isotope | /r/HasProperty | known in addition
Facets:
Source sentences:
text: Natural erbium is a mixture of 6 stable isotopes; in addition, 10 radioactive isotopes are known.
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.
text: Natural erbium is a mixture of 6 stable isotopes; in addition, 10 radioactive isotopes are known.