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Democritus believed all matter was made of extremely small particles that could not be divided. He called these particles, atoms.
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Democritus thought liquid particles were round and smooth, but atoms in a solid were rough and prickly.
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Dalton Proposed the theroy that all matter is made up of individual particles called atoms, which cannot be divided.
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J.J. Thomson discovered Plum Pudding in 1897 and put together the "Plum Pudding" model in 1904.He Believied that electrons were surrounded by a soup or cloud of positive charge.
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Ernest Ruthford states that an atom has a dense, positively charged nucleus. Electronsmove randomly in the space around the nucleus.
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In Niel's Model, the electrons move in spherical orbits at fixed distances from nucleus.
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Erwin Schrodinger develops mathmatical equationk to describe the motion of electrons in atoms. His work leads to the eledtron cloud model.
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James Chadwick, a british physicist, confirms the existence of neutrons, which have no charges. Atomic nuclei contain neutrons and positively charged particles.
