Assertion: xenon | /r/HasAspect | 8 stable isotopes
Facets:
Source sentences:
text: Xenon has 8 stable isotopes and more than 30 unstable isotopes.
text: It has nine stable isotopes and seven known radioactive isotopes.  
text: Xenon has eight stable isotopes.
text: Xenon has 8 stable isotopes and more than 30 unstable isotopes.