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