Assertion: noble gas's isotope | /r/HasProperty | radon
Facets:
Source sentences:
text: Later, when isotopes were numbered instead of named, the element took the name of the most stable isotope, radon, while Tn was renamed 220Rn and An was renamed 219Rn, which caused some confusion in the literature regarding the element's discovery as while Dorn had discovered radon the isotope, he had not been the first to discover radon the element.
text: The noble gas family consists of six different elements, five of which have stable isotopes (helium [He], neon [Ne], argon [Ar], krypton [Kr], and xenon [Xe]), and one that only has radioactive isotopes (radon [Ra]).