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Thales was the investigate the basic principles (atom). His atomic model was based on human senses.
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Democritus created the first atomic theory. He came up with the word 'atom'.
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Aristotle didn't believe in the atom, because it put restrictions on gods. He believed in the four elements: fire, air, water, earth.
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Newton believed that matter is formed of solid, massy impenetrable particles and atoms are held together by attractions or forces.
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Dalton had the atomic theory experiment. His atomic theory was:
1. All matter is made up of tiny particles called atoms.
2. All atoms of a given element are alike, but are different from the atoms of any other element.
3. Compounds are formed when atoms of different elements combine in fixed proportions.
4. A chemical reaction involves a rearrangement of atoms, not a change in the atoms themselves. -
Becquerel discovered radiation using the uranium experiment.
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Thompson used a cathode ray tube to discover electrons. He discovered the plum pudding model.
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Milliken used the Oil Drop Experiment to find the charge of individual electrons.
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Alpha particles were fired through a thin gold sheet into a zinc sulfide sheet. Rutherford found a portion of the atom was positively charged and relatively heavy.
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Rutherford used the Gold Foil Experiment to discover the nucleus and proton. With this, he created the nuclear atom model. He believed that the atom is mostly empty space with all the positive charge within the nucleus.
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Bohr created the Bohr Model for the atom.
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Aston discovered isotpes using the mass spectrograph.
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Schrodinger used math equations to find the probablity an electron would be in a certain position. He created the Quantum Mechanical atom model.
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Chadwich discovered the neutron.
