Evolution Of The Atomic Model

By Cheyliaodell
  • 1941 BCE

    Glenn Seaborg

    Discovered eight transuranium elements over a course of 10 years starting in 1941
  • 400

    Democritus (400 B.C)

    All matter is made up of units called atoms.

  • Isaac Newton

    Proposed a mechanical universe with solid, and small masses in motion

  • John Dalton

    Elements consist of atoms that were identical, but an "atomic theory" is based upon atoms with measurable properties of mass.

  • Micheal Faraday

    Developed the laws of electrolysis

  • J. Plucker

    Built one of the first cathode-ray tubes (gas discharge tube).

  • Dmitri Mendeleev

    Created the periodic table/ laws

  • James Clerk Maxwell

    Proposed the theory of electromagnetism and made the connection between light and electromagnetism waves.

  • G.J Stoney

    Theorized that electricity was compromised of negative particles he called, electrons.

  • Sir William Crookes'

    Experiments with cathode-ray tubes which led him to confirm the work of earlier science

  • E. Goldstein

    Discovered canal rays (they have a positive charge equal to an electron.

  • Wilhelm Roentgen

    Discovered X-rays

  • Henri Becquerel

    Discovered radiation by studying the effects of X-ray on photographic film

  • J.J Thomson

    Determined the charge to mass ratio in radiation.

  • Rutherford

    Discovered alpha, beta, and gamma, rays in radiation.

  • Marine Sklodowska Curie

    Discovered radium polonium and coined the term radioactivity after studying the decay process of uranium and thorium.

  • Max Planck

    Proposed that an object that glows and produces heat emits light

  • Fredrick Soddy

    Created the term “isotope” to explain the unintentional breakdown of radioactive elements

  • Hantaro Nagaoka

    Presented that an atomic model called Saturnian Model to discribe the structure of an atom

  • Richard Abegg

    Found that inert gases have a “stable electron configuration”

  • Hans Geiger

    Invented a device that could detect alpha particles

  • H.G.J Moseley

    Discovered that the number of protons in an element determines its atomic number

  • Francis William Aston

    Used a mass spectrograph to identify 212 isotopes

  • Niels Bohr

    Suggested an atomic structure theory that stated the other orbit of an atom could hold more electrons than the inner orbit

  • Louis de Brogille

    Proposed that electrons have a wave/ particle duality.

  • Cockcroft / Walton

    Created the first nuclear reaction, producing alpha particles

  • Paul Dirac

    Proposed the existence of anti-particles

  • James Chadwick

    Discovered neutrons, particles whose mass was close to that of a proton.

  • Lise Meitner, Hahn, Strassman

    Discovered nuclear fission

  • Enrico Fermin

    Created the first man-made nuclear reactor