History of the Atom

  • 400

    Democritus

    Democritus
    Developed idea of the atom.
  • Antoine Lavoisier

    Antoine Lavoisier
    Created the Law of Conservation of Matter
  • John Dalton

    John Dalton
    Developed the theories that all matter is made up of atoms, all atoms of a given element are identical in mass and properties, and that compounds are formed by combination of two or different kinds of atoms.
  • J.J. Thomson

    J.J. Thomson
    He discovered the electron while experimenting with cathode rays. He created a atom model, but excluded protons.
  • Marie Curie

    Marie Curie
    Discovered radioactivity with her husband, Pierre, while studying Uranium and Thorium.
  • Max Planck

    Max Planck
    Created the idea of ‘quanta’ which was that energy didn’t flow continuously, but came out in small sections
  • Albert Einstein

    Albert Einstein
    Developed the equation of light speed and mas and explained why visible motion of particles occurred. He also wrote the general theory of relativity and helped Bohr with the uncertainty principle.
  • Robert Millikan

    Robert Millikan
    He discovered the photoelectric effect while measuring the charge carried by a single electron.
  • Ernest Rutherford

    Ernest Rutherford
    Discovered different types of radiation, discovered the atomic nucleus, and developed the model of an atom. He worked with Frederick Soddy to prove his theory on atoms of radioactive elements.
  • Niels Bohr

    Niels Bohr
    He proposed that electrons had a set distance from the nucleus and that as an atom absorbed energy it got closer to the nucleus and vice versa if it lost energy. This proposition was based on other scientists theories.
  • Louis De Broglie

    Louis De Broglie
    Developed theory of electron waves that was based of a proposal Einstein had made 20 years earlier.
  • Werner Heisenberg

    Werner Heisenberg
    Developed the uncertainty principle while wondering about basic quantum properties of electrons. He did so at the Institute for Theoretical Physics where he met Niels Bohr.
  • Erwin Schrodinger

    Erwin Schrodinger
    Developed Schrödinger's wave equation that he based off of Bohr's model. His equation is similar to Heisenberg's, but his is more widely preferred.
  • James Chadwick

    James Chadwick
    Proved the existence of the neutron and found it’s mass while repeating experiments of Fredric and Irene-Joliot Curie.