Radon is an odorless, colorless, noble gas in its natural state. It is one of the heaviest gases known, and it is toxic and known to produce lung cancer in people. Radon as an atomic weight of 222, a melting point of - 96 °F, and a boiling point of - 79.1 °F. Radon does not have many commercial uses as it is so toxic. However there are some uses of radon and these include: in hydrologic research, geologic studies, and atmospheric studies.