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Democritus believed that all matter consisted of small particles that couldn't be divided. He talked about his theory making others believe his theory was right.
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Aristotle beleived all substances were built from four elements: fire,water,earth, and air. Created a diagram showing the elements and hot,cold,dry, and wet.
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His theory said all elements are composed of atoms. Also all atoms of the same element have the same mass, and atoms of different elements have different masses. Created spheres to illustrate what atoms looked like.
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Thomson used electric current to study atoms. He hypothesized that a beam has a stream of particles that interact with the air in the tube he created. Some refer to his model as the "plum pudding." Model showed that the negaitve and positive charges are balanced.
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His theory was that electrons move with constant speed in fixed orbits around the nucleus. He drew a atom with electrons orbiting it.
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He suggests that an atom has a central nucleus. Electrons orbit this center nucleus. Drew a diagram of his theory.
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Determined the unit charge of an electron in 1909 with his oil drop experiment. e = 1.60 x 10-19.
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He discovered that uranium emits fast moving particles that have a positive charge. With help from Marsden he shot a beam of light at a gold piece to see where light travels first.
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Came up with the equation E=mc2. E represents energy, m represents mass, and c² is the square of the speed of light.
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Used mathmatical equations to describe the movement of electrons. His model was made into an electron cloud.
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Helped with Rutherfords theory and model. He was one of Rutherfords students. He helped with the gold piece and beam of light model.
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He confirmed there are neutrons. Neutrons stabalized the repeal of the positive protons.
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Said moving particles such as electrons have some properties of waves. He tested his theory by shooting electrons at nickle.
