~~J.J.+Thompson~~

=J.J. Thomson= 18 December 1856 – 30 August 1940 Born in Manchester, England Year of discovery: Published his work in 1897 []

JJ Thomson was more then a great physicist, he was a great teacher, as 7 of his students received Nobel prizes, as did his son. Born to Scottish parents, he grew up in Manchester. His father died when he was 16. He studied engineering at trinity college in Cambridge.

His greatest discoveries revolve around the discovery of the electron with his cathode ray tube experiments. in these, crooks tubes with a near perfect vacuum have high dc voltage passed between two electrodes. this results in the excitement of electrons and they pass the length of the tube and into a detecting device. [] Before Thomson, the reason this happened wasn't understood. Thomson did three crooks tube experiments: the first was to confirm that a negative charge was produced by the stream observed, the second was to see if this stream could be influenced by magnetic fields, and the third was to calculate the mass-to-charge ration of the particles he observed. the results of his last two experiments are the critical ones in the discovery of the electron. they showed that rather then particles or massive atoms that are just a little negative, they are purely negative particles with an infinitesimal mass and a massive charge.

It also spawned a new view of the atom. Rather then a solid sphere Thomson viewed it more as a "plum pudding," being a spherical emulsion of positive and negative particles grouped together randomly. []

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