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Democritus questioned if matter could be divided forever. His theory was that matter could not be divided forever but his theory was ignored because of unanswered questions and higher authority in that field. People such as Aristotle and Plato disagreed with his work and so did the people.
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Lavosier developed the Law of Conservation of Mass.
This law said that elements were pure substances and cannot be broken down -
In 1803 English chemist John Dalton proposed the atomic theory and came up with 4 postulates
1) Each element is composed of extremely small particles called atoms
2)All atoms of a given element are identical, but they differ from those of any other element.
3)Atoms are neither created nor destroyed in any chemical reaction
4)A given compound always has the same relative numbers and kinds of atoms -
Michael Faraday studied the effect of electricity on solutions
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Dmitri created the first periodic table.
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Crookes discovered many things about the cathode ray. He discovered that the rays move in a straight line, that it causes glass to illuminate and many more.
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Wilhelm Roentgen discovered x-rays
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Henri Becquerel discovered radioactivity
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J.J proposed that there was something smaller in size compared to an atom. He was correct and it was electrons. J.J discovered electrons.
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J.J proposed that there was something smaller in size compared to an atom. He was correct and it was electrons. J.J discovered electrons.
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They discovered the radioactive elements radium and polonium
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He developed the idea of quanta which is a discrete unit of energy
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Einstein discovered the relationship between energy and mass
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He invented the Geiger counter which counts alpha particles
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His oil drop experiment determined the mass and charge of an electron
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Ernest discovered the proton and the nucleus of the atom.
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Ernest discovered the proton and the nucleus of the atom.
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He claimed that electrons are arranged in circular orbits around the nucleus
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He introduced wave mechanics
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He discovered the neutron
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He created the chain reaction for the atomic bomb