• 300


    Democritus called the particles pf matter atoms. Picture credited to: Google,com
  • John Dalton

    John Dalton
    John Dalton said matter is made of spherical solid masses in motion. picture credited to:
  • Wilhelm Roentgen

    Wilhelm Roentgen invented the x-ray in 1895
  • J.J. Thompson

    J.J. Thompson descibed the atom as a ball of positive charge containing a number of electrons.
  • Ernest Rutherford

    Ernest Rutherford
    Ernest Rutherford used his "gold foil" experiment to determine that the nuecleus of an atom is dense and had a positive charge. Thus, discovering the proton . He assumed that the electrons were outside the nucleus of an atom. Picture creditied to:
  • X-Rays

    The first x-ray was used for medical purposes.
  • Niels Bohr

    Niels Bohr
    Niels Bohr explained the atomic structure of the atom as "sucessful orbital shells of electrons".His model is known as the Bohr planetary model. picture creditied to:
  • Niels Bohr (agian)

    Neils Bohr won a nobel prize for his work with the atomic theory.
  • de Broglie and Schrodinger

    de Broglie and Schrodinger
    de Broglie and Schrodinger identified the electron cloud as the probable location of moving electrons. picture credited to:
  • James Chadwick

    James Chadwick
    James Chadwick discovered a particle with the nucleus that has a mass similar to that of a proton. He is credited with discovering the neutorn. picture credited to:
  • Atomic Bomb

    The first atomic bomb waas dropped to end ww II