Atomic Theory Timeline

  • 400


    Democritus found the atom.All atoms are indivisble, Atom derives from atomos. Atomos is greek for indivisible.
  • John Dalton

    John Dalton
    He proposed atomic theory, with spherical solid masses in motion. Atoms can't be made or destroyed.
  • Wilhelm Roentgen

    Wilhelm Roentgen
    While using a CRT, he observed nearby chemicals that glowed. Some of the rays weren't deflected by the magnetic field. He these rays X-Rays. This is based on
  • J. Plucker

    J. Plucker
    He built the first Cathode Ray tube. These are used to make X-Rays.
  • JJ Thomson

    JJ Thomson
    He described atoms as ball of postive charge containing a number of electron, discovered the electron.
  • Aston

    Discovered the existence of isotopes through the use of a mass spectrograph.
  • Neils Bohr

    Neils Bohr
    He is the Father of Quantam theory, Proposed that the atom is "succesive or bital shells of electrons. Bohr camee up with the "Bohr Planetary Model."
  • Ernest Rutherford

    Ernest Rutherford
    He is the father of nucleus physics. He developed the "gold foil experiment." Rutherford deteremined that the nucleus of an atom is very dense and has a positive charge.
  • Erwin Schrodinger

    Erwin Schrodinger
    He proposed the "Electron Cloud Theroy." Schrodinger identified the electron cloud as the propable location of moving particles.
  • James Chadwick

    James Chadwick
    Chadwick proved the existance of neutron. He discoverd a particle within the nucleus that has a mass similar to that of a proton.
  • John Douglas Cockcroft/ Ernest Thomas Sinton Walton

    John Douglas Cockcroft/ Ernest Thomas Sinton Walton
    Built the early linear accelerrator and bombarded lithium with protons to produce alpha particles. They split the atom for the first time. This later lead to the atomic bomb that ended World War 2.
  • Ernest Lawrence

    Ernest Lawrence
    He invented the cyclotron and recognized the potential for medical isotopes. Isotopes are used to make medicines. When radioactive isotopes are introduced to the body, they give off an energy or radiation that can be tracked by imaging equipment. This allows doctors to more efficiently pinpoint exactly where the diseased tissue is. Image scanning using radioactive isotopes is more finely detailed and more accurate than MRI scans
  • Enrico Fermi

    Enrico Fermi
    He conducted the first chain reaction releasing energy from the atoms nucleus.
  • First Atomic Bomb dropped

    First Atomic Bomb dropped
    The atomic bomb was dropped to finish World War 2. America used Cockroft and Walton's idea, and split the atom to create a nucleur bomb.