Atomic Timeline

By 28bcasimir
  • 440 BCE

    Plato

    Plato
    Solid forms of matter are made of indivisible elements shaped like triangles, believed only 4 elements earth, fire, water, air.
  • 400 BCE

    Democritus

    Democritus
    Atoms are uniform, solid, hard, incompressible indestructible, and move in infinite numbers through empty space until stopped.

  • Robert Boyle

    Robert Boyle
    Believed everything was made of extremally tiny particles.

  • Antone Lavvoisier

    Antone Lavvoisier
    Explained matter is made of atoms which cannot be created or destroyed in chemical reactions.

  • Billiard Ball Model

    Billiard Ball Model
    The Billiard Ball Model depicts atoms as spherical.

  • John Dalton

    John Dalton
    Preposed all matter is made of atoms which are indivisible.

  • Amedeo Avogradro

    Amedeo Avogradro
    equal volumes of gasses at the same temperature and pressure contain equal numbers of molecules.

  • Dmitri Mendeleev

    Dmitri Mendeleev
    Arranged elements according to value of atomic weights present periodicity of properties (arranged periodic table).

  • JJ Thompson

    JJ Thompson
    All atoms contain small negatively charged subatomic particles (electrons).

  • Solar System Model

    Solar System Model
    The Solar System Model depicts atoms consisting of a nucleus and orbiting electrons.

  • Pierre and Marie Curie

    Pierre and Marie Curie
    Discovered Radioactivity.

  • Plum Pudding Model

    Plum Pudding Model
    The Plum Pudding Model shows electrons have a negative charge in a sea of positive charge.

  • Plum Pudding Model

    Plum Pudding Model
    The Plum Pudding Model shows electrons have a negative charge in a sea of positive charge.

  • Albert Einstein

    Albert Einstein
    Any liquid is made of molecules.
    molecules are always in random ceaseless motion.

  • Robert Millikan

    Robert Millikan
    Electrons have a discrete quantifiable charge.

  • Ernest Rutherford

    Ernest Rutherford
    Atoms are tiny dense positively charged core (nucleus).

  • Niels Bohr

    Niels Bohr
    Explained some physical quantities only take discreate values.

  • Henry G.J. Mosely

    Henry G.J. Mosely
    Thought that the frequency of x-ray emitted is proportional to the atomic number.

  • Erwin Schrodinger

    Erwin Schrodinger
    Erwin Schrodinger said electrons do not follow sharply defined orbits.

  • Electron Cloud Model

    Electron Cloud Model
    The Electron Cloud Model shows the area around the nucleus that electrons are most likely to be found.

  • James Chadwich

    James Chadwich
    James Chadwich proved the existence of neutrons.

  • The Alchemists

    The Alchemists
    Believed all metals were made formed from 2 principals mercury and sulfur.