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Democritus hypothesised that everything is comosed of atoms.
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Published book containing well, founded concept of chemical elements and the verification of the law of conservation of matter in chemical reactions.
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Established the law of definite proportions for chemical compounds.
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Proposed the atomic theory, said atoms are spherical and solid with masses based on a measurable properties of mass.
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Introduced name 'Cathode Rays' and began expiriments leading eventually to the discovery of the positive counter part, canal rays. Also suggested aurora is due to cathode rays from the sun.
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determined the charge to mass ration of an elction = 1.7459x108 coulombs/grams by using CRT. Also, canal rays were associated with the proton H+.
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Insolated radium and polonium. Awarded nobel prize for phsics in 1903, and nobel prize for chemistry in 1911.
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Determined the mass and charge to an electron.
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Identified positively charged particles (protons) which gave atoms most of its mass, he proposed that had a small positive nucleus that was surrounded.
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Declared the atomic numbre was the number of protons and neutrons, thus, leading to the rearrangement of the periodic table.
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Developed an atomic model that had atoms built up successive or bital shells of electrons
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Proposed wave mechanical theory of the hydrogen atom. Was awarded Nobel prize for physics with Paul Dirac.
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Obtained 1st alound chamber photograph of cosmic rays. These showed that the rays either wave, or produced, many changed, high energy particles.
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Discovered a neutral atomic particle with a mass close to a proton. Thus was discovered the neutron.
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Discovered that when an atom splits, it makes a huge explosion with alot of radiation.