atomic theory Jayson

By PMurphy
  • 400

    Democrius

    Propsed the matter is made of small unbreakable particless called atoms
    shape of atom determined the properties of that substance
    coined term atoms cont to divide matter until cannot be dived any more empty space between atoms atoms are solid
  • 400

    aristole

    started that all substances are made of 4 elements
    1 fire
    2 water
    3 air
    4 earth

  • John Dalton

    Transformed Democritus ideas on atoms into a modern atomic model . All matter is made of tiny microscope particles called atoms. The atoms of the same element are indentical . Atoms of differnt elements combine in small whole# ratios toform compounds. Chemical reactions involve the combinations of atoms .No new atoms are created . Law of simple Multiple proportions.

  • J.J.Thompson

    Discovered the electron . Conducted the cathode ray tube experiment. By adding an electric charge he found that the moving piecies were negtavive opposites . The Plum Pudding model displays electrons embeeded in a sphere of postive material.

  • Robert Millikan

    Determined the mass uctedand charge of the electron. Conducted oil drop experiment by measureing the effectvof an electric on very small oil droplets. From the velocity of the drop and the charge on the plates he calculated the mass on a electron.

  • Ernest Ruterford

    Discovered the nucles. Did a experiment on the gold foil. Made two major concluisons from gold foil experiment. The nucleas is made up of mostly + charge mass. The atom containsa postive piece at center. Atom has nucleas. elecctrons orbit nucleas. nucleas is dense mass made up of protons.

  • Neils Bohr

    Proposed that an electron is found only in specfic circular paths or orbitaround the nucleas. Refferd to as plantearymodelbecause electrons move around the nucleas like planets around the sun. He had a diagram called Lithuim Atom.

  • Sir James Chadwick

    Confirmed the exsitence ofneutron in the nuecleas . The atom is mostly empty space. The atom consits of 2 regions. Nucleaus in center and contains protons and neutrons. The electron cloud is the region where electrons in areas of high nuecleas called atomic mass