The Radon Symbol is the chemical symbol for the element Radon, which is a radioactive, colorless, odorless, tasteless noble gas. It has the atomic number 86 and is represented by the symbol RN. Radon is a naturally occurring element that can be found in rocks and soil, and it is the heaviest known gas. It is also the second most abundant noble gas in the Earth's atmosphere. Radon is a health hazard when it accumulates in enclosed spaces, such as homes and buildings, and can cause lung cancer if inhaled in large amounts.