Assertion: radon | /r/HasProperty | unstable gas
Facets:
Source sentences:
text: Odorless and invisible, radon has been classified (by the Environmental Protection Agency) as a carcinogen since 1988, and is the leading cause of cancer among nonsmokers in of the U.S. Because radon is an unstable gas, it breaks down and dissipates quickly in the open air.
text: Because radon is an unstable gas, it breaks down and dissipates quickly in the open air.