Antoine Henri Becquerel (1852-1908) is known as the man who discovered radioactivity—a discovery that influenced the development of atomic weapons, nuclear energy, and radioactive medical treatments.
Becquerel was born on December 15, 1852, in Paris, France. Both his father, Alexandre Edmond Becquerel, and his grandfather, Antoine Cesar Becquerel, one of the founders of electrochemistry, were physicists.
Becquerel worked as an engineer as well as a professor of physics. His discovery of radiation occurred in February 1896. A few months before, Wilhelm Roentgen had discovered X rays—invisible penetrating forms of radiation. Becquerel wanted to find out whether or not phosphorescent materials—materials that glow in the dark after being stimulated by sunlight—would also give off X rays. What he discovered was that certain substances, such as uranium, would give off X rays even when they had not been stimulated by light.
Soon scientists discovered that other elements give off energy in this way. These are the radioactive elements, whose atoms are decaying. Particles from the atoms break away and release the energy that held the atoms together. When harnessed, this produces the enormous energy needed to produce nuclear power.
In 1901, while experimenting with radium, Becquerel developed what looked like a reddish-brown sunburn on his skin. He reasoned that the burn was caused by the radium—that the rays emitted were able to penetrate and cause changes to living things. His discovery led to the controlled use of radioactivity in the treatment of some diseases. For his discoveries he was awarded, along with Marie and Fierre Curie, the Nobel prize in physics in 1903.
Becquerel died on August 25, 1908, in Le Croisic, France