Atomic Theory

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    Democritus

    Democritus
    He hypothesized that all matter was indivisible into smaller parts than the atom. This atom is the building block of all things.
  • Sir Isaac Newton

    Sir Isaac Newton
    Newton proposed a mechanical universe where small solid masses move in motion.
  • John Dalton

    John Dalton
    He descirbed atoms as being "sypherical solid masses in motion", which means they're always moving. Also, atoms are rearranged, not changed completely.
  • W.C. Roentgen

    W.C. Roentgen
    He found that he had produced a previously unknown "invisible light," or ray, that was being emitted from the tube, letting him see bones or medal of whatever he wanted to look at. He named the new ray X-ray, because in mathematics "X" is used to indicated the unknown quantity.
  • JJ Thomson

    JJ Thomson
    Thomson discovered the electron. He said that there were balls of energy with positive charges containing electrons. His model was known as the "Chocolate-Chip Cookie Model". He also used cathode rays in his experiments.
  • Ernest Rutherford

    Ernest Rutherford
    He did the Gold Foil experiment which showed that the nucleus of the atom is dense and has a positive charge, thus discovering the proton. Also, he said that atoms are mostly empty.
  • Schrodinger

    Schrodinger
    He came up with the "Electron Cloud model" as showing the probable location of moving particles using a mathematical description.
  • Neils Bohr

    Neils Bohr
    Bohr explained that the structure of the atom as successive orbital shells of electrons. Also, he said that electrons have a certain amount of energy. His experiment or model was called the "Bohr Planetary Model".
  • James Chadwick

    James Chadwick
    Chadwick discovered a particle within the nucleus that has a mass similar to a proton, but no charge, thus discovering the neutron.
  • Cockroft and Walton

    Cockroft and Walton
    The both came up the accelration of protons where they bombarded lithium with high energys or protons and succeded in transmitting it to helium. It was one of the earliest experiments to change the atomic nucleus of one element to a different element by artificial means or by splitting the atom.
  • Oppenheimer

    Oppenheimer
    He built a bomb using uranium and splitting the atom to wipe out most of Japan in World War II.