Radon - Rn
Radon is colorless at standard temperature and pressure and it is the most dense gas known. At temperature below it's freezing point is has a brilliant yellow phosphorescence. It is chemically unreactive, it is highly radioactive and has a short half life.
Radon was sometimes used in hospitals to treat cancer and was produced as needed and delivered in sealed gold needles. Radon is used in hydrologic research, because of it's rapid loss to air. It is also used in geologic research and to track air masses.
Radon in the environment
Radon can be found in some spring water and hot springs. There is anyway a detectable amount of radon in the atmosphere. Radon collects over samples of radium 226 at the rate of around 0.001 cm3/day per g of radium.
Back to chart periodic table of elements.