Atomic Timeline

  • The Alchemists
    500 BCE

    The Alchemists

    They Discovered a material that would alter common metal into silver or gold.
  • Plato
    428 BCE

    Plato

    A Greek philosopher that came up with these 4 elements fire, water, earth, and air.
  • Democritus
    400 BCE

    Democritus

    Atomic Theory stated that all matter's made of small indestructible units called atoms.
  • Robert Boyle

    Robert Boyle

    Regarded today as the first modern chemist and one of the founders of modern chemistry.
  • Antone Lavoiser

    Antone Lavoiser

    French chemists invented the first periodic table which had three elements. He also named hydrogen and oxygen.
  • Billiard Ball Model

    Billiard Ball Model

    Discovered by John Dalton. Saying atoms were the smallest particles of matter.
  • John Dalton

    John Dalton

    Stated all elements consisted of atoms that were identical had the same mass, and compounds were atoms from different elements combined.
  • Amadeo Avagadro

    Amadeo Avagadro

    He stated that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
  • Dmitri Mendeleev

    Dmitri Mendeleev

    Created the Periodic Table. Known as the Father of the Periodic Table.
  • JJ Thompson

    JJ Thompson

    Create a charge to matter ratio of electrons.
  • Plum Pudding Model

    Plum Pudding Model

    Discovered by J J Thompson. He said atoms were spheres of positive electricity with negative particles throughout.
  • Pierre and Marie Curie

    Pierre and Marie Curie

    They discovered radioactivity and two new elements on the periodic table which consist of Radium and Polonium.
  • Albert Einstein

    Albert Einstein

    He proved the existence of atoms and said that any liquid is made up of molecules.
  • Robert Millikan

    Robert Millikan

    Found the change of an electron with his oil drop test or experiment.
  • Ernest Rutherford

    Ernest Rutherford

    Finished a tiny dense, positively charged nucleus as the result of the alpha particles scattering gold foil experiment.
  • Neils Bohr

    Neils Bohr

    He was a physicist who established an atomic structure theory that said the outer orbit of an atom could hold more electrons than the inner orbit.
  • Henry G. J. Mosely

    Henry G. J. Mosely

    Found the number of protons in an element and its atomic number.
  • Electron Cloud Model

    Electron Cloud Model

    Discovered by Erwin Schrodinger and Werner Heisenberg. Stated an atom consists of a dense nucleus and many proton and neutrons and are surrounded by electrons, but all atoms have different energy levels in different charges.
  • Solar System Model

    Solar System Model

    Rutherford and Bohr contributed to this model. Rutherford said the atom is mainly empty space with a nucleus that has a positive charge surrounded by negative electrons. Also, Bohr said they circulate the atom.
  • Erwin Schrodinger

    Erwin Schrodinger

    He created wave and quantum mechanics.
  • Werner Heisenberg

    Werner Heisenberg

    He discovered a key piece of quantum theory which is the uncertainty principle stating particles' position and momentum can't both be known fully.
  • James Chadwich

    James Chadwich

    He discovered neutrons and particles.