Montreal, Canada/canada220
Previous | Home | NextCase B. A closeup of the apparatus diagram directly demonstrating the emanation from thorium is a gas which can be condensed to a liquid. A current of air is passed over thorium oxide (far left) through a plug of cotton and then water to remove any possible particulate or water-soluble radioactive material. The gas stream is then passed through a copper spiral before being carried on to the electrometer, which detects a radioactive gas. When the copper spiral is cooled in liquid air, the radon condenses and the radioactivity in the electrometer ceases. As the condensed radon is warmed, it evaporates and radioactivity in the electrometer is once again detected. Soddy and Rutherford determined the temperature at which this condensation, and evaporation occurs, thus determining the boiling point of radon.
