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Atomic Theory AndersonT_Hour 6

By crystalvc
  • 460

    Democritus

    Democritus
    Born 460BC
    Died 370BC
    1. Was an influential ancient greek pre-socratic philosopher primarly remembered today for his formulation of an atomic theory of the universe.
    2. His mentor Leucippus origonally came up with the atomic theory, but it was then adopted by Democritis.

  • John Dalton

    John Dalton
    Born Spetember 6, 1766
    Died July 27, 1844
    1. Proposed the modern theory of the atom on September 3rd, 1803.
    2. First to recognize that the pressure of a mixture of gases is the sum of the contributes of the individual components of the mixture.

  • JJ Thomson

    JJ Thomson
    Born December 18th, 1856
    Died August 30, 1940
    1. In 1897 discovered the electron
    2. In 1895 discoverd x-rays, Thomson demonstrated that cathode rays were actually some speedily moving particles.

  • Marie Curie

    Marie Curie
    Born November 7, 1867
    Died July 4, 1934
    1. Was a Polish and neutralized French physicist and chemist who conducted pioneering research on radioactivity.
    2. Deduced that there were other substances besides uranium that were very radioactive such as polunium and radium, which she discovered in 1898.

  • Max Planck

    Max Planck
    Born April 23, 1858
    Died October 4, 1947
    1. Was a German theoretical physicist quantam theory, which won him a Nobel Prize in physics in 1918.
    2. In 1901 he devised a theory that perfectly described the experimental evidence, but partof it was a radical new idea.

  • Albert Einstein

    Albert Einstein
    Born March 14, 1879
    Died April 18, 1955
    1. Was a German born theoretical physicist and philosoper of science. He developed the general theory of relativity, one of the two pillars of modern physics.
    2. In a 1905 paper, Einstein postulated that light itself consists of localized particles.
    3. In 1907, Einstein proposed a model of matter where each atom in a lattice structure is an indpendent harmonic oscillator.

  • Ernest Rutherford

    Ernest Rutherford
    Born August 30, 1871
    Died October 19, 1937
    1. The Rutherford Model of the atom was simplified in a well known symbol showing electrons circling around the nucleus like planets orbiting the sun.
    2. In 1908 Rutherford was awarded with a Nobel Prize in chemistry.

  • Neils Bohr

    Neils Bohr
    Born October 7, 1885
    Died November 18, 1962
    1. In 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus.
    2. Bohr's starting point was to realize that classical mechanics by itself could never explain the atoms stability.

  • James Chadwick

    James Chadwick
    Born October 20, 1891
    Died July 24, 1974
    1. Pursued a line of research that led to his discovery of the neutron in 1932 and went on to measure the mass.
    2. Also in 1932 he anticipated that neutrons would become a major weapon in the fight against cancer.