JJ+Thomson+-+Discovery+of+the+Electron

=J.J. Thomson =  http://nobelprize.org/nobel_prizes/physics/laureates/1906/thomson-bio.html **Date of Birth- December 18, 1856 Date of Death- August 30, 1940 Place of Origin- Manchester, England. Year of Discovery- 1897**

J.J. Thomson’s successes started early, as he was already enrolled at Owens College, when he was only 14 years old. Six years later, he put his name down for Trinity College in where he later became a Fellow of Trinity in 1880. Before his primary discovery, he had a renowned interest in the atomic structure. He even wrote several papers on the subject, mainly His //Application of Dynamics to Physics and Chemistry,// //Notes on Recent Researches in Electricity and Magnetism,// and his Adams Prize winning //Treatise on the Motion of Vortex Rings//. He even went as far as to go to America deliver four lectures all of which were later known published as //Discharge of Electricity through Gases//.

In 1897, J.J Thomson performed several experiment consisting of electricity and a cathode ray tube. This tube is a “glass vacuum tube into which an electron gun emits a flow of electrons guided by an electrical field towards a screen covered in small phosphorescent elements.” J.J Thomson was confused with this neon like lights, just like all scientist of his time. The question amongst them were whether the beams of light were actual light waves or solid mater. However with more experiment, he concluded that these mysterious rays are streams of particles much smaller than atoms, they are in fact minuscule pieces of atoms, AKA, the electron. (ALIA) 


 * //The Plum Pudding Model...//**

J.J. Thompson formed the plum pudding model of an atom which attempted to explain why an atom’s charge was electrically neutral. The plum pudding model of an atom was formed in a way that could be easily described to people outside of the scientific world in a very basic and common manner. The pudding in the model represents a positive charge and takes up the majority of the atom. The plums with in the pudding are described as having a negative charge and together with the positive pudding, the electron is therefore neutral.

Today, the model of an atom contrasts in many ways, but the importance of Thompson’s model is that he tried to explain the neutrality of atoms. In theory his idea of negative particles and positive particles causing a neural charge is accurate but the way in which it actually appears in an atom is a lot different. In Thompson’s model, the positive charge was encompassing the entire atom, but today we know that the positive charge is only found with in the nucleus in the center of the atom. The model was soon disprooved as accurate when Rutherford's gold foil experiment showed that some positive particles deflected. The only way that this could be explained was to assume that the positive particles were not "pudding-like" and were focused in the center of the atom.



[]