Essay on The Physics Of The Atomic Theory

1040 Words Sep 28th, 2015 null Page
Within a little over two millenniums, the history of the atomic theory changed multiple times. In the very beginning, Democritus was the very first to propose the existence of the particle (H). The name he would give this particle was atomos. Aristotle believed that each element of the earth; water, air, fire, and earth, would gradually become small every time they were halved. This view held up for about 2,000 years. The next major change within the scientific field that concerned atoms was when John Dalton proposed his Atomic Theory in 1803. The atomic theory is, all matter is made up of atoms, atoms are indivisible and indestructible, and finally compounds are formed by two or more different kinds of atoms. J.J. Thomson, discovered that electrons are negatively charged, and proposed the plum pudding model. The model is based off of a dominance of large protons in the atoms with small electrons dispersed around the positive protons to keep the atom neutral. Ernest Rutherford tested his own experiment of using gold foil and a concentrated beam that shot out particles. If J.J. Thomson’s plum pudding model was correct, then the particles would shoot straight through the gold foil and only leave black marks on the direct other side of the foil. When Rutherford performed this experiment, he found that there were black marks on the sides of the foil that suggested that it reflected off of the gold foil along with appearing on the other side. With this experiment disproving…

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