Atomic Model and Theory Timeline

By MM8763

  • Isaac Newton

    Isaac Newton
    Theorized a mechanical universe with small, solid masses in motion.

  • John Dalton

    John Dalton
    Proposed an 'atomic theory' with spherical solid atoms, and that elements consisted of atoms that were identical and had the same mass.

  • Dmitri Mendeleev

    Dmitri Mendeleev
    Created the first periodic table.

  • J. J. Thomson

    J. J. Thomson
    Determined the charge to mass ratio of electrons.

  • Ernest Rutherford

    Ernest Rutherford
    Discovered the alpha, beta, and gamma rays in radiation.

  • Hantaro Nagaoka

    Hantaro Nagaoka
    Proposed an atomic model called the Saturnian Model to describe the structure of an atom.

  • Richard Abegg

    Richard Abegg
    Discovered that inert gases had a stable electron configuration which led to their chemical inactivity.

  • Ernest Rutherford

    Ernest Rutherford
    Performed the gold foil experiment to come to a conclusion that atoms were mainly empty space and they had a dense core, called the nucleus.

  • Niels Bohr

    Niels Bohr
    Proposed an atomic theory that stated the outer orbit of an atom could hold more electrons than the inner orbit.

  • James Chadwick

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