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600 BC
Declared all life came from water. Everything was made of water. -
460-370 BC
thought everything was made of atoms -
thought everything was earth, water, air, and fire
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Thought that atoms moved around and were small
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- elements are made of extremely small particles called atoms
- atoms of a given element are identical in size, mass, and other pe=roperties;
- atoms cannot be subdivided, created, or destroyed 4.atoms of different elements combine in simple whole number ratios to form chemical compounds
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descovered radioactivity
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descovered electron (two thousand times lighter than hydrogen)
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atoms contain a nucleus made of protons surrounded by electrons
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determined the charge and mass of an electron
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Ruthaford fired helium atoms at a gold sheet of paper but they hit the nucleus and bounced back. He didn't think they would
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Created bohr model and said everthing was on fixed paths and couldn't be inbetween
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Descovered and studied isotopes. Also did the whole number rule
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made the quantum model
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discovered evidence towards the existance of Neutons