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Democritus, Ancient Greek philosopher theorizes the concept of invisible "atomos" or as we know, atoms.
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Timeland of Atomic discoveries
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In 1772, Antoine Lavoisier theorized, the conservation of mass. A theory that states that all of the matter and mass we first had, we'll always have.
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Benjamin Franklin, one of America's founding fathers, discovers positive and negative charges of atoms.
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The theory developed by John Dalton, that atoms can be distinguished by their different weights.
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Joseph Proust creates the law of definite composition, stating that "A compound always contains two or more elements combined in a definite proportion by mass"
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During the 1860's Dmitri Mendeleev created the concept for the Periodic table of elements.
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Wilhelm Roentgen, November 8th 1895 created--accidently--the X-Ray.
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(Only month and year are accurate)Henri Becquerel, a French scientist while conducting an experiment with uranimum, discovered radioactivity.
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JJ Thompson discovers the Electron of an Atom.
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Marie and Pierre Curie, French Chemists, husband and wife, discovered radioactivity in 1898.
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Max Planck develops the Quantum theory. That light must be emitted and absorbed in a discrete amount. A radiation formula. (Please ignore the date though the year is accurate)
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Albert Einstein discovered the photoelectric effect of atoms in 1905.
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Robert Millikan first realized the charge of electrons through conducting various experiments.
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Henry Moseley, in 1914 created atomic number concept for elements.
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In 1918 Ernest Rutherford discovered that an atom can in fact be an Ion.
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The image of the atom we know today was created by Niels Bohr in 1922. It is called the Atomic Model, (Only year is accurate)
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The Austrian physicist, Erwin Schrodinger creates the first model of a whole atom with interacting waves.Hence the electron cloud. (Please ignore the date but the year is accurate)
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James Chadwick, an English scientist discovered the nucleus of an atom.
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In 1938, Otto Hahn, Lise Meitner, and Fritz Strassmann were the first to split the atom by filling it with neutrons.
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Enrico Fermi, produced the first Nuclear chain reaction in 1942.
