| In 1899, Robert B. Owens, an American physicist, observed that some new substance appeared during thorium decay. This new substance may be removed from thorium solutions by air flow. Rutherford, who was teaching at McGill University in Montreal, Canada, concluded that thorium compounds continuously emit a radioactive gas which retains the radioactive powers for several minutes. He called this gas "emanation", from Latin "emanare" - to elapse and "emanatio" - expiration. In 1900, Friedrich Ernst Dorn in Germany and Andre-Louis Debierne in France confirmed the findings of Rutherford as radium emanation. Rutherford, Ramsay and Soddy showed that thorium emanation is a new element of the noble gas family named radon. |
| Noble Gas Radon is one of the rarest of natural elements. The outer 1.6 km deep layers of the Earth& |