Atomic Theory Timeline

By WholeGrainMilk
  • 440 BCE

    Democritus

    Democritus
    Atoms are "uncuttable"
    Atoms are small, hard particles
  • 440 BCE

    Democritus Atom Model

    Democritus Atom Model
    Democritus' Atom model
  • Period: 440 BCE to

    Atomic Theory Timeline

  • John Dalton

    John Dalton
    All substances are made of atoms
    Atoms of different elements are different
    Atoms of the same element are exactly alike
    Elements combine in specific proportions
    He conducted experiments in combining elements

  • John Dalton Atom Model

    John Dalton Atom Model

  • J.J Thomson

    J.J Thomson
    Conducted the cathode-ray tube experiment
    Theory lead to the "plum-pudding" model
    There are small, negatively charged particles inside an atom

  • J.J Thompson Atom Model

    J.J Thompson Atom Model

  • Ernest Rutherford

    Ernest Rutherford
    Most of an atom's mass is in the nucleus
    There is a small, dense, positively charged nucleus
    Conducted the gold foil experiment
    Electrons move in empty space in the atom
    Atoms contain mostly empty space

  • Ernest Rutherford Atom Model

    Ernest Rutherford Atom Model

  • Niels Bohr

    Niels Bohr
    Electrons jump between levels from path to path
    Electrons travel in definite paths

  • Niels Bohr's Atomic Model

    Niels Bohr's Atomic Model

  • Erwin Schrodinger and Werner Heisenberg

    Erwin Schrodinger and Werner Heisenberg
    Electron paths cannot be predicted.
    Electrons are found in Electron Clouds, not paths.

  • Erwin Schrodinger and Werner Heisenberg Atomic Model

    Erwin Schrodinger and Werner Heisenberg Atomic Model