Atomic Model Timeline

By 28SEspitia
  • 500 BCE

    The Alchemists

    The Alchemists
    The Alchemists devoted untold grueling hours to transmute metals into gold. The Alchemists where not an instant success.
  • 427 BCE

    Plato

    Plato
    Plato theorized that solid forms of matter are composed of elements.
  • 400 BCE

    Democritus

    Democritus
    Democritus theorized that all material bodies are made up of indivisibly small atoms.

  • Antone Lavoisier

    Antone Lavoisier
    Antone Lavoisier determined that oxygen was a key substance in combustion, and he gave the element its name.

  • Amedeo Avogadro

    Amedeo Avogadro
    Avogadro studied the properties of electricity and liquids, but his best known work was with gases. It was known by 1809 that all gases, when heated equally, expand by the same amount.

  • John Dalton

    John Dalton
    He introduced the atomic theory into chemistry and for his work on human optics. He discovered all matter is made of atoms.

  • Dmitri Mendeleev

    Dmitri Mendeleev
    Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. He is best known for formulating the Periodic Law and creating a version of the periodic table of elements.

  • Henry G. J. Mosely

    Henry G. J. Mosely
    He discovered a systematic mathematical relationship between the wavelengths of the X-rays produced and the atomic numbers of the metals that were used as the targets in X-ray tubes.

  • JJ Thompson

    JJ Thompson
    He achieved an original study of cathode rays culminating in the discovery of the electron, which was announced during the course of his evening lecture to the Royal Institution.

  • Pierre and Marie Curie

    Pierre and Marie Curie
    Pierre and Marie Curie discovered the existence of the elements radium and polonium.

  • Albert Einstein

    Albert Einstein
    He mathematically proved the existence of atoms.

  • Robert Millikan

    Robert Millikan
    He successfully determined the magnitude of the electrons.

  • Ernest Rutherford

    Ernest Rutherford
    He established that the mass of the atom is concentrated in its nucleus.

  • Neils Bohr

    Neils Bohr
    Neils Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus.

  • James Chadwick

    James Chadwick
    he proved the existence of neutrons- elementary particles devoid of any electrical change.

  • Robert Boyle

    Robert Boyle
    He discovered that the volume of a gas decreases with increasing pressure and vice versa.