Atomic Model Timeline

By amadeopoopycaca
  • 428 BCE

    Plato

    Plato
    Introduced that ideal geometric forms serve as atoms.
  • 400 BCE

    Democritus

    Democritus
    All bodies are made up of individual small atoms.
  • 330 BCE

    Solar system model

    Solar system model
    When electrons went from an outer orbit to an inner orbit, the color of the light was dependent on the energies of the orbits.
  • 500

    The Alchemists

    The Alchemists
    They believed that there were 7 base elements

  • Robert Boyle

    Robert Boyle
    Demonstrated that matter is made up of tiny particles.

  • Antone Lavosoisier

    Antone Lavosoisier
    The total mass of products and reactants in a chemical reaction is always the same.

  • Billiard ball model

    Billiard ball model
    The Billiard Ball model is a model of the atom proposed by John Dalton.

  • John Dalton

    John Dalton
    Proposed all matter is made up of indestructible atoms. He also calculated the first relative weights of the atom.

  • Amedeo Avogadro

    Amedeo Avogadro
    Stated that equal volumes of gases at equal temperature and pressure contain the same number of particles.

  • Dmitri Mendeleev

    Dmitri Mendeleev
    Discovery of the periodic law, which states that when elements are arranged in order of increasing atomic weight the table displays a recurring pattern of properties within groups of elements.

  • Pierre and Marie Curie

    Pierre and Marie Curie
    Discovered radioactivity.

  • JJ Thomson

    JJ Thomson
    Proposed the plum pudding model.

  • Plum pudding model

    Plum pudding model
    that electrons are negatively charged subatomic particles and that atoms have no net electric charge. The plum pudding model has electrons surrounded by a volume of positive charge, like negatively charged "plums" embedded in a positively charged "pudding".

  • Albert Einstein

    Albert Einstein
    Mathematically proved the existence of atoms and their random, ceaseless motion

  • Robert Millikan

    Robert Millikan
    Accurate demonstration of the charge carried by an electron.

  • Ernest Rutherford

    Ernest Rutherford
    Proposed the nuclear model of the atom based on his gold foil experiment.

  • Neils Bohr

    Neils Bohr
    Showed the atom was a small positively charged nucleus surrounded by orbiting neutrons.

  • Henry G.J. Mosely

    Henry G.J. Mosely
    Demonstrated that the major properties of elements are determined by the atomic number of their weight.

  • Electron cloud model

    Electron cloud model
    Theory of quantum mechanics that describes the location of electrons as a cloud around the nucleus of an atom.

  • James Chadwich

    James Chadwich
    Proved existence of neutrons.