The Atom

Part I of Essay
AP Physics Period 2 In the spring of 1897 J.J. Thomson demonstrated that the beam of glowing matter in a cathode-ray tube was not made of light waves, as "the almost unanimous opinion of German physicists" held. Rather, cathode rays were negatively charged particles boilin ....

Part II of Essay
.... dinner. Armed with the electron, and knowing from other experiment that what was left when electrons were stripped away from an atom was much more massive remainder that was positively charged, Thomson went on in the next decade to develop a model of the atom that came to be called the "plum pudding" model. The Thomson atom, "a number of negatively electrified corpuscles enclosed in a sphere of uniform positive electrification" like raisins in a pudding, was a hybrid: particulate electrons and diffuse remainder. It served the useful purp ....