Radon

Radon is a gas produced by the radioactive decay of the element radium. Radioactive decay is a natural, spontaneous process in which an atom of one element decays or breaks down to form another element by losing atomic particles (protons, neutrons, or electrons). When solid radium decays to form radon gas, it loses two protons and two neutrons. Thses two protons and two neutrons are called an alpha particle, which is a type of radiation the elements that produce ratioation are coalled radioaacitve. Radon itself is radioactive because it also decays, losing an alpha particle and forming the element polonium.