In (Prince winter of early five), December 15, 1852, Henri Becquerel, the discoverer of the natural radioactivity of born.



Henri Becquerel (Henri Becquerel, 1852, 1908, 25 days), French physicist. The discovery of the natural emission phenomenon, (lsjt.org) won the 1903 Nobel Prize in Physics. (L $ j��.c��)
Becquerel, the choice of material is uranium and potassium sulphate. He let these two materials are exposed to the sun, and then with black paper material exposed photographic film package together. Negatives, rinsed after a period of time and shows the image of the uranium crystals.
Becquerel to the conclusion that: "radiant energy emitted by the phosphorescent material through the opaque paper. Beginning, he thought the uranium will absorb the energy of the sun, and then emit X-rays. the
in Paris, February 26, 1896 and 27 days, the sky is cloudy, Becquerel originally intended wrapped uranium and photographic film to the sun, had returned to the drawer. March 1, he rinse the film, originally thought to only see fuzzy images not think they see a very clear image, so he surprised. Uranium does not require external sources of energy, such as sunlight also can emit radiation, he found radioactive materials spontaneously emit radiation.
Review: accidentally discovered the problem, he became a famous scientist.