Radon is a natural radioactive element, an invisible noble gas, and its periodical chart symbol is Rn. You can’t see it, taste it or smell it. It is a colorless, odorless, tasteless gas that may be an undetected problem in your home or building and exists in every home and building. Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil, rock, water and natural construction and building materials, such as Granite, stones and gravel. As Uranium breakdowns, it produces a byproduct called Radon gas.