ELA Component

For my ELA connection, I completed a newspaper article about the discovery of the electron.

January 17, 1897

A new subatomic particle has just been discovered. Scientists J.J. Thomson accomplished this using a Crookes tube. Before Thomson's experiments, it was already known that the cathode rays deposited an electric charge. This was shown by placing an electrometer at the opposite end from the cathode and anode. The electrometer measured an electric charge when the cathode rays hit. J.J. Thomson's first experiment was completed to determine if the charge was separate from the cathode rays. Thomson bent the cathode rays away from the electrometers using a magnet and discovered that the electrometers stopped measuring electric charge. Thomson consquently concluded that the electric charge and the cathode rays must be combined rather than separate entities. Thomson then conducted second experiment to determine the charge of the cathode rays. He placed two metal pieces in a Crookes tube/cathode ray tube and connected them to a power source. A ray shot out of the first metal piece and through the second metal piece in a straight line. Thomson then placed two metal plates of opposite charges on opposite sides of the tube. This caused the ray to bend towards the metal plate of positive charge. After seeing this, Thomson concluded that the cathode ray was negatively charged based on the fact that opposite charges attract. Thomson revealed that his experiments have given him hope of making new important discoveries to learn more about this subatomic particle.

Citations:

Tyler DeWitt. “Discovery of the Electron: Cathode Ray Tube Experiment.” Online video clip. Youtube. Youtube, 27 Nov. 2012. Web. 17 Nov. 2014.