Atomic Timeline

  • The Alchemists
    500 BCE

    The Alchemists

    The Alchemists found a substance that made silver or gold with more common elements.
  • Plato
    427 BCE

    Plato

    Introduced the atomic theory with atoms were ideal geometric figures.
  • Democtritus
    400 BCE

    Democtritus

    Theorized that unsplit table small atoms made all materials in bodies.
  • Robert Boyle

    Robert Boyle

    Published the Scopticel about how all matter is composed of important particles from which all materials are constructed.
  • Antoine Lavoisier

    Antoine Lavoisier

    Found out the reactants and the total mass of products in a chemical reaction is always the same.
  • John Dalton

    John Dalton

    Theorized that all matter was made of atoms, indestructible building blocks, and were indivisible. Different elements were made of different sized and mass.
  • Billiard Ball Model

    Billiard Ball Model

    Didn't show any nucleus or electrons and defined an atom to be a ball like structure.
  • Dmitri Mendeleev

    Dmitri Mendeleev

    Proved the arrangement of elements in the order of their increasing atomic weights.
  • Robert Milikan

    Robert Milikan

    Found out that electrons charge was always a multiple of precisely determined charges.
  • JJ Thompson

    JJ Thompson

    Theorized that tiny negatively charged subatomic electrons or particles were found in atoms.
  • Pierre and Marie Crie

    Pierre and Marie Crie

    Theorized one of the reason atoms break down are radioactive particles.
  • The Curies

    The Curies

    Discovered the existence of the element's radium and polonium.
  • Plum Pudding Model

    Plum Pudding Model

    Was made to explain two properties of the atom.
  • Albert Einstein

    Albert Einstein

    Einstein helped revolutionize science through the use of statics and probability by mathematically proving atoms exist.
  • Neils Bohr

    Neils Bohr

    Proposed an atomic structure thing that said the inner orbit of an atomic held less electrons than the outside.
  • Solar System Model

    Solar System Model

    Showed hoe the electrons orbit about the nucleus at different distances.
  • Henry G. J. Mosely

    Henry G. J. Mosely

    Proposed that the number of positive charges in the atomic nucleus is the atomic number.
  • Ernest Rutherford

    Ernest Rutherford

    Proposed that nearly all of an atom is empty space, so when alpha particles go through the empty space the nucleus has a very little reaction.
  • Electron Cloud Model

    Electron Cloud Model

    Predicts the likely location of the electron based on a fraction of probability.
  • Erwin Schrodinger

    Erwin Schrodinger

    Created the first electron cloud model.
  • James Chadwich

    James Chadwich

    Discovered the Neutron in atoms.
  • Almadeo Avogrado

    Almadeo Avogrado

    Discovered that elements were not only found in individual atoms but instead be found in molecules.