Antoine Henri Becquerel (December 15, 1852 - August 25, 1908) was a French physicist and the discoverer of radioactivity. After R繹ntgen's discovery of x-rays, Becquerel noted an unknown energy that was emitted from uranium salts. He left a rock and a well-wrapped photographic plate in his desk drawer and found that the plate, though unexposed to light, had developed patterns which would ordinarily indicate exposure.be called radioactivity. His student Marie Curie, and her husband Pierre showed that thorium also emitted what were then called Becquerel rays. In 1900 Becquerel isolated electrons in radiation, and in 1902 he presented the first evidence of radioactive transformation. In 1903, he shared the Nobel Prize in Physics with the Curies "in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity". He developed serious burns on his skin from handling radioactive stones and died in 1908 at the age of 55.