3, 4 The electron was the first subatomic particle discovered Electron was found when Joseph John Thomson and Robert Millikan studied the cathode ray tube. They found that the cathode ra particles were much lighter than ydrogen atoms, indicating that the atom was not the smallest particle of matter Robert Andrews Millikan Joseph John Thomson Now we know that (1868-1953): excelled in his wan one of the first director of electrons determine experimental designs and the famous cavendish many of a material s conclusions, in addition to Laboratory of Cambridge research he also spent much University in England, Where properties, including time preparing textbooks so almost all the discoveries chemical reactivi that his student didn t have to concerning subatomic particles color, etc rely so much on lectures and their behavior were made3.4 The electron was the first subatomic particle discovered Electron was found when Joseph John Thomson and Robert Millikan studied the cathode ray tube. They found that the cathode ray particles were much lighter than hydrogen atoms, indicating that the atom was not the smallest particle of matter. Now we know that electrons determine many of a material’s properties, including chemical reactivity, color, etc. Joseph John Thomson, wan one of the first director of the famous Cavendish Laboratory of Cambridge University in England, Where almost all the discoveries concerning subatomic particles and their behavior were made Robert Andrews Millikan (1868-1953) :excelled in his experimental designs and conclusions, in addition to research, he also spent much time preparing textbooks so that his student didn’t have to rely so much on lectures