Discuss and define radioactivity. Introduce the early work of Becquerel and Rutherford and their discovery of radioactive decay ores. Stress that the result of the decay is to produce a nuclei which is more stable than the original. Introduce alpha, beta, and gamma rays. Discuss alpha particles as helium nuclei with a mass of 4 and an atomic number of 2. Show transmutation of uranium by alpha particle decay. Work the alpha particle decay for plutonium and radium.