Atom

History of the Atom

By jayy1182
  • 440

    Democritus

    Born: 460 BC
    Died: 370 BC
    "by convention bitter, by convention sweet, but in reality atoms and void"
    came up with the four natural elements; water, earth, air, fire. http://craigjm.tripod.com/physics.html
    http://atomictimeline.net/index.php

  • John Dalton

    John Dalton
    Born: September 6, 1766
    Died: July 27, 1844
    Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass. he preposed that atoms are tiny solid shperes

  • James Maxwell

    James Maxwell
    Born: June 13, 1831
    Died: November 5, 1879
    Proposed electric and magnetic fields filled the void http://atomictimeline.net/index.php

  • Marie Curie

    Marie Curie
    Born: November 7, 1867
    Died: July 4, 1934
    Studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre also discovered the radioactive elements polonium and radium. She discovered Radium and Polonium. Her dicovery was made in 1898 http://atomictimeline.net/index.php

  • Ernest Rtuerford

    Born: August 30, 1871
    Died: October 19, 1937
    Ernest Rutherford bombarded gold foil with helium nuclei ( alpha particles ) and noticed that most go through the gold undeflected. But approximately 1 in 8000 were perceptibly deflected into all directions and some even bounced back in the direction they came.

  • Niels Bohr

    Niels Bohr
    Born; October 7, 1885
    Died: November 18, 1962
    He was 77 when he died
    Niels Bohr applies quantum theory to Rutherford's atomic structure by assuming that electrons travel in stationary orbits defined by their angular momentum. CItes; https://www.google.com/search?q=Niels+bohr&source=lnms&sa=X&ei=ZElxUvTPIMiL2wXG1oDwBg&ved=0CAYQ_AUoAA&biw=1280&bih=929&dpr=1#psh=["1",{"null":[5]}]

    http://www.rsc.org/chemsoc/timeline/pages/1913.ht

  • Henry Mosely

    Henry Mosely
    Born: November 23, 1887
    Died: August 10, 1915 In 1913, English physicist Henry Moseley observed the properties of x-rays from about a dozen consecutive elements in the periodic table. In doing so, he discovered that the wavelength of the x-rays became shorter as the atomic weight increased. http://mrcauseysworld.com/chemistry/atomic_number.html

  • Louis de Broglie

    Louis de Broglie
    Born: August 15, 1882
    Died: March 19, 1987
    In his 1924 thesis he postulated the wave nature of electrons and suggested that all matter has wave properties. https://www.google.com/#hl=en&q=louis+de+broglie+

  • Werner Heisenburg

    Werner Heisenburg
    Born: December 5, 1901
    Died: February 1, 1976
    1926 German physicist Werner Heisenberg formulated his uncertainty principle which says that you cannot know by measurement the position and momentum of a particle simultaneously. http://www.aip.org/history/heisenberg/p01.htm

  • James Chadwick

    James Chadwick
    Born: October 20, 1891
    Died: July 24, 1974
    In 1932, Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons - elementary particles devoid of any electrical charge. http://jameschadwickatomictheory.weebly.com/

  • Murry gell-Mann and George Zweig

    Murry gell-Mann and George Zweig
    murry:
    Born: September 15, 1929
    Zweig:
    Born: May 30, 1937 Zweig and the American physicist Murray Gell-Mann, working independently of each other, proposed their theory in 1964. Zweig originally called the particles aces; Gell-Mann coined the term quarks. Quarks are the “building blocks” of which protons and neutrons are made. http://www.hyperhistory.com/online_n2/people_n2/science_n2/atomic_theory.html