Born: Paris, France, 15 December, 1852
Died: Le Croise, August 25, 1908
Becquerel came from a family of physicists. His grandfather helped found the electrochemical industry in France and his father was particularly interested in fluorescence and phophoresence which occur when matter aborbs light on one wavelength and emits it on another.|
Becquerel continued with the work of his father, and after the discovery of X-rays by Roentgen, he experimented with a fluorescent compound, potassium uranyl sulfate, and photographic paper, attempting to prove that X-rays are produced in fluorescence. Instead, he discovered that no light at all was required to produce the X-rays. The uranium in the compound consistently emitted radiation in all directions. In 1898, this phenenomen was named radioactivity by Marie Curie.
By 1899 Becquerel had established that the particles could be affected by a magnetic field and that they were negatively-charged electrons, identical to those produced by a cathode-ray tube. In 1901 he identified uranium as the source of the charged particles.
This discovery was the first real proof of the particle nature of atoms and led to further discoveries by Einstein.
Becquerel was awarded a share in the 1903 Nobel Prize for physics, along with Pierre and Marie Curie.