Atomic theory

devan and taylor atomic timeline

By 950795
  • 460

    Democritus

    Democritus
    He stated all matter is composed of eternal,
    indivisible, indestructable and indefinately small
    substances that cling together.

  • Dalton

    Dalton
    -originated the modern atomic theory in the early 19th century. The atomic theory was that all atoms were indestructible particles and have the same atomic weight.
    -He said atoms were spheres beacuse spheres were the "divine shape"

  • Thompson

    Thompson
    -Discovered the electron
    -Proposed a new model of the atom
    -Said the tiny negative charge electrons must be
    embedded in a cloud of posative charge since atoms
    have no charge.
    -Plum-pudding model, 1904, the atom is composed of electrons

  • Rutherford

    Rutherford
    -His theory tells us an atom consists of a small,
    dese, positively charged nucleous with electrons
    around it.
    -Gold foil experiement: It measured the deflection
    of alpha particles that were directed onto a sheet of gold foil

  • Goldstein

    Goldstein
    Eugen Goldstein is best known for his studies of electric discharges in gases at low pressures in 1886. Cathode rays were invisible emanation coming from the discharge tube. It showed that rays could give off a sharp shadow and that they emitted perpendicular to the cathodes surface. He also realized that they can be deflected by a magnetic field. Cathode ray tubes with a perforated cathode can emit a glow from the end where the cathode is.

  • Erwin Schrodinger

    Erwin Schrodinger
    Erwin Schrodinger was an Austrian physicist who helped contribute to quantum mechanics. He developed the Schrodinger equation which describes how the quantum state of a physical system changes over time. This equation has been universally celebrated as one of the most important achievements of the twentieth century, and a landmark in quantum mechanics,physics and chemistry.

  • James Chadwick

    James Chadwick
    Chadwick proved the existence of neutrons. He defined neutrons as elementary particles devoid of any electrical charge. In contrast with the helium nuclei (alpha rays) which are charged, and therefore repelled by the considerable electrical forces present in the nuclei of heavy atoms, this new tool in atomic disintegration need not overcome any electric barrier and is capable of penetrating and splitting the nuclei of even the heaviest elements.