- For Bequerel, the SI unit of radioactivity, see Becquerel.
Antoine Henri Becquerel (December 15, 1852 – August 25, 1908) was a French physicist, Nobel laureate, and one of the discoverers of radioactivity.
Early days
Becquerel was born in Paris into a scientific family which, including him and his son, produced four generations of scientists. He studied science at the École Polytechnique and engineering at the École des Ponts et Chaussées.
Rise in natural sciences, discoveries and major works
In 1892 he became the third in his family to occupy the physics chair at the Muséum National d'Histoire Naturelle. In 1894 he became chief engineer in the Department of Bridges and Highways.
In 1896, Becquerel accidentally discovered radioactivity while investigating phosphorescence in uranium salts. Investigating the work of Wilhelm Conrad Röntgen, Becquerel wrapped a fluorescent mineral, potassium uranyl sulfate, in photographic plates and black material in preparation for an experiment requiring bright sunlight. However, prior to actually performing the experiment, Becquerel found that the photographic plates were fully exposed. This discovery led Becquerel to investigate the spontaneous emission of nuclear radiation. In 1903 he shared the Nobel Prize in Physics with Pierre and Marie Curie "in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity".
Image of Becquerel's photographic plate which has been fogged by exposure to radiation from uranium salts. The shadow of a metal
Maltese Cross placed between the plate and the uranium salts is clearly visible.
Final days and legacy
In 1908, the year of his death, he was elected permanent secretary of the Académie des Sciences. He died at the age of 55 in Le Croisic.
The SI unit for radioactivity, the becquerel (Bq) is named after him, and also there are Becquerel craters on the Moon and Mars.
See also
External links
