THOMPSON, RUTHERFORD, AND BOHR Three scientists of the late 1800’s and early 1900’s help us with discovering what we know today about the atom. These three scientists are JJ Thompson, Ernest Rutherford, and Niels Bohr. They used and created models of the atom and ideas we still use today. JJ Thompson used the cathode ray and its electric currents for his experiments. Above the tube, he placed one positively charged plate and one negatively charged one. He found that the ray bent in the direction of the positive plate instead of straight down the tube. He found that the particles in the cathode ray must be negative because opposite charges attract. He named the negative charges electrons. Using the cathode ray, Thompson also discovered the mass of an electron is smaller than the mass of an atom. Also that the atom is NOT indivisible, proving Dalton wrong. And he proposed since there is a negative charge in the atom, there must be a positive one to balance the neutral atom out. The previous model of the atom was a solid, neutral sphere with the same matter all throughout, but, with Thompson’s new findings he created a new model. His new model of the atom was a positively charged sphere with both positive and negative charges and electrons all mixed through. His findings created Thompson’s model of the atom. Ernest Rutherford, one of Thompson’s students, worked off Thompson’s model and idea to help understand the atom, and in the future teach his own students. Two of Rutherford’s students set up the gold foil experiment to see if Thompson’s model was correct. Positively charged alpha particles were shot through a sheet of gold foil and an apparatus around the foil was used to shine a light whenever the particles hit. Rutherford thought the particles would go straight through the gold foil with little change in their path, but was surprised when some of the