1875-1900

**Antoine Henri Becquerel** -Born in Paris, France on December 15, 1852. **
 * [[image:Becquerel.JPG width="188" height="263" align="left"]]
 * -Died in Le Croisic, France on August 25 1908. **


 * Antoine Henri Becquerel was a French physicist born into a scientific family extending through several generations. The most famous of all is his grandfather Antoine-Cesar Becquerel. ** Becquerel was French physicist and Nobel laureate, who discovered radioactivity. He was the son of Alexandre Becquerel (1820-91), who conducted studies into light and phosphorescence and invented the phosphoroscope, and grandson of Antoine Cesar Becquerel (1788-1878), one of the founders of electrochemistry. Becquerel became professor of physics at the Museum of Natural History in 1892 and at the Polytechnical School in 1895.

 “BECQUEREL, Antoine Henri” __Funk and Wagnall’s Encyclopedia__ 1992-1995 ed.
 * Becquerel made an accidental discovery. In 1896, he accidentally discovered the phenomenon of radioactivity while he was studying the capability of uranium salts that had been exposed to sunbeams to fog photographic film plates. Since there were bad weather conditions, he could not expose the sample to sunlight. However, he accidentally left it on top of the photographic plate. When he developed the plate, he found out that the uranium salt still fogged the plate. Therefore, he proved his point that something that was very alike to X rays was released by luminescent substance at the same time it threw off visible radiation. His works awaken the world for the discovery of new radioactive materials. **

** -Born in Manchester, England on December 18, 1856.  -Died in Cambridge, UK on August 30, 1940. British physicist and Nobel laureate. **Thompson entered Owens College. His professor of mathematics noticed his extraordinary intelligence and motivated him to apply for a scholarship at Trinity College in Cambridge. He was a student who finished the third year of math with first-class honors. He became Cavendish Professor of Physics in 1884. He was also president of the Royal Society from 1915 to 1920 and professor of natural philosophy at the Royal Institute of Great Britain from 1905 to 1918. **  “THOMPSON, Sir Joseph John” __Funk and Wagnall’s Encyclopedia__ 1992-1995 ed.
 * Sir Joseph John “JJ” Thompson
 * Thompson was awarded the 1906 Nobel Prize in physics for his work on the conduction of electricity through gases. JJ Thompson discovered the electron in 1897. He performed many experiments that involved passing electric current at a low pressure through gases. In glass tubes, he sealed the gases and at both ends the tubes were fitted with metal disks called electrodes. These electrodes were attached to a source of electricity. The outcome was a glowing beam or cathode ray that traveled from the cathode to the anode. His investigations into the action of electrostatic and magnetic fields would later result in the invention of the mass spectrometer. **