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Plato introduced the atomic theory in which ideal geometric forms serve as atoms, according to which atoms broke down mathematically into triangles, such as the form elements had the following shape.
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This model was made by Plato
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Democritus held a theory that everything is composed of atoms, which are physically, but not geometrically, invisible, that between atoms, there lies empty space.
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Aristotle thought that all materials on earth were not made of atoms, but of the four elements, earth, fire, air, and water. He believed all substances were made up of small amounts of these four elements of matter.
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His major contribution to the atomic theory was that he helped develop a definition of an element. He also helped people change the way they think about science.
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Lavoisier found the total mass of products and reactants in a chemical reaction that is always the same.
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His most important contribute to science was that matter is composed of atoms of differing weights and combine in simple ratios by weight.
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John Dalton discovered the Solid Sphere of Billiard Ball Model.
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Mendeleev found that when all the known chemical elements were arranged in order increasing by atomic weight.
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Marie and her husband Pierre Curie discovered Polonium and Radium and was awarded a Nobel Prize in physics and chemistry for her discovery of the two elements.
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Thomoson proposed a model of the atom as a sphere of positive matter with electrons positioned based on electrostatic forces.
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J.J. Thomson made this model.
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Einstein mathematically proved the existence of atoms and helped revolutionize al the sciences through the use of statistics and probability.
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Millikon succeeded in precisely determining the magnitude of the electrons charge
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Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of Radioactive decay.
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Neils proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in a certain well defined quantities.
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Mosely demonstrated that the major properties of an element are determined by the atomic number, not by the atomic weight
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Made by Werner and Erwin
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Werner developed a key piece of the quantum theory, the uncertainty principal, with profound implications.
