1. The Discovery of the Electron BY THONNY KOON

2. J.J. Thomsom  Third Cavendish Professor of Experimental Physics in 1884.  Studied Cathode Rays  At the time many people thought the rays were an ethereal disturbance like light  Thomson believed the rays were made of particles.

3.  Uses two metal plates (one positively charged and one negatively charged) to deflect cathode rays.  Accomplishes this by creating a vacuum in the tube.  Since the rays moved towards the positively charged plate, it was determined that the particles had a negative charge.

4.  J.J. ran a current through a coil of wire to produce a magnetic field.  J.J positioned the coils so that the magnetic field deflects the rays in the opposite direction to the deflection produced by the electric field from the metal plates.  The fields were adjusted so that the rays were deflected evenly and thus the forces were balanced

6. Results  Found a charged particle that had a charge two thousand times greater than a hydrogen ion.  These particles were also two thousand times lighter than hydrogen and therefor can pass between atoms in a solid.  J.J called these particles corpuscles.  1891- G. Johnstone Stoney coined the term electron

7. Works Cited  http://www- outreach.phy.cam.ac.uk/camphy/electron/elect ron5_1.htm http://www- outreach.phy.cam.ac.uk/camphy/electron/elect ron5_1.htm  https://www.aip.org/history/electron/jjelectr.htm https://www.aip.org/history/electron/jjelectr.htm