  No. Radon is a colorless, radioactive, inert gaseous element formed by the radioactive decay of radium. It is used as a radiation source in radiotherapy and to produce … neutrons for research.Its most stable isotope is Rn 222 with a half-life of 3.82 days.adon is a common byproduct of the decay of radioactive elements like radium and uranium present in Earth's crust. Until recently it was used in radiation treatment for cancer … , and is still used in Geiger counters.