The phenomenon of radioactivity was first discovered by Henry Becquerel in 1896. He was using naturally fluorescent minerals to study the properties of X-rays. He exposed potassium uranyl sulphate to sunlight and then placed it on photo-graphic plates wrapped in black paper. Becquerel developed his photographic plates and found the images to be strong and clear, giving a strong proof that uranium independently emitted radiation without any external energy source. Becquerel had discovered radioactivity. The term radioactivity was actually coined by Marie Curie, who with her husband Pierre, began investigating the phenomenon discovered by Becquerel. They extracted uranium from ore and found that the leftover ore showed more radioactivity than the pure element uranium. This led to the discovery of the elements polonium and radium. In 1903, Becquerel and the Curies received a joint Nobel prize in Physics for their contribution in the radioactivity field. This award was for their discovery of radioactivity and their other contributions in the field of radioactivity.
Radioactivity
