how is radon used and what is it made of??

Answer 1

Radon is a radioactive noble gas considered an indoor air pollutant and cancer agent. It is trapped under houses and in basements as it makes it's way to the surface of the Earth from underlying bedrock. Check out wikipedia for all the info:
http://en.wikipedia.org/wiki/Radon

Answer 2

Radon is an element; the heaviest inert gas. It's radioactive with a half-life of 3.85 days. It hasn't got any uses that I know of, in fact it's a nuisance. It's produced by the radioactive decay of radioactive elements in minerals and, being heavy, it collects underground in caves, mines, spring water and the basements of houses. Breathing it is bad news. Being an alpha particle emitter it causes cancer, especially lung cancer. Radon contamination of house basements is a serious problem in several parts of the world, including the UK and Britain, especially places with cold climates where houses are sealed against draughts. In hot countries it usually isn't much of a problem. If it's a problem where you live, the solution is easy; a small electric pump to continuously suck the air from the floor of your basement and vent it outside.