e same indestructible model proposed by Dalton. A man named Milikin determined the mass of an electron to be 0 amu and the relative charge to be negative 1. With the discovery of these electrons by Thompson and the discovery of protons several years later Thompson was able to devise a new model of the atom. Thompson stated that protons and electrons were evenly distributed throughout the atom. This model was labeled the "plum-pudding model". Thompson described the atom as a gooey mass of positively charged particles (protons) with raisins (electrons) embedded all around it.Ernest Rutherford was a major contributor to the atomic model because he proved that although Dalton and Thompson were partially correct there was still a flaw in both of their models of the atom. Rutherford devised an experiment to either prove or disprove Dalton's model and or Thompson's model. Rutherford and his assistants put a piece of radioactive material in a lead box with a small hole in one side to direct the alpha particles towards the gold foil, which was surrounded by zinc sulfide screens. The zinc screens showed flashes of light where the alpha particles were going to go, straight through (Thompson's model) or straight back (Dalton's model). To his astonishment particles were through, came back, and some also were deflected to the sides of the gold foil. He proved that Dalton and Thompson were incorrect and the atom consisted mostly of space. At the center of this space is a very small core, called the nucleus, which can justify the deflected particles. Rutherford established that the mass of the atom is concentrated in its nucleus. He found that an electron is 1/1836 the mass of a proton and he also proposed that electrons travel in orbits around the nucleus.With all of these alterations to the theory of an atom a few, five to be exact, problems arose. One of the major problems was the size of an atom. If each electron had its own orbital and the atom h...
