Wednesday, September 9, 2009

9-9-09 The Atom

Discovery of the Atomic Nucleus
  • 1911- Ernest Rutherford, Hans Geiger, and Ernest Marnden conducted the golden foil experiment.
  • Discovered a very densely packed bundle of matter with a positive charge in the atom. Rutherford named it the nucleus

Composition of the Atomic Nucleus

  • Made of protons and nuetrons
  • Protons have a positive charge equal in magnitude to the chare of an electron
  • Atoms/elements are electrically nuetral because they contain an equal number of protons and electrons
  • Nuetrons have no charge
  • Nuclei of atoms of different elements diifer in number of protons and nuetrons and therefore the amount of positive charges they posses.
  • The amount of protons determines that atom's identity

Forces in the Nucleus

  • When 2 protons are extremely close, there is a strong attraction between them. This attraction also exists between close neutrons or a proton and a nuetron that are close to each other.
  • The forces that cause these attractions are nuclear forces.

The Sizes of Atoms

  • radius-- distance from center of the nucleus to the outer portion of its electron cloud
  • Atomic radii are expressed in picometers (pm).
  • atomic number(Z)- the number of protons in each atom of an element

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10 comments:

  1. Kyle McCafferySeptember 9, 2009 at 3:58 PM

    http://www.youtube.com/watch?v=gO9CKkbLUiI

    This video is a good explanation of the Rutherford experiment with a little humor added in it.

    http://www.youtube.com/watch?v=5pZj0u_XMbc&NR=1

    This video has a good atomic view of the gold foil experiment. Its towards the end.

    ReplyDelete
  2. Matt OriansSeptember 9, 2009 at 5:00 PM

    http://micro.magnet.fsu.edu/electromag/java/rutherford/
    This website talks more about the golden foil experiment and also has a great illustration of how it worked.

    ReplyDelete
  3. DuklewskiSeptember 9, 2009 at 5:18 PM

    Very, very in depth break down of the expirement

    the diagrams helped me

    http://library.thinkquest.org/19662/low/eng/exp-rutherford.html

    ReplyDelete
  4. joe "kitty" krebsSeptember 9, 2009 at 5:18 PM

    This website talks about the atom, nuclear force, protons, neutrons, and electrons. It also includes questions.

    http://www.edcenter.sdsu.edu/epic05-hoover-chem/index.html

    ReplyDelete
  5. (The) David RaySeptember 9, 2009 at 6:09 PM

    This webstie explains nuclear force in a way.
    http://aether.lbl.gov/elements/stellar/strong/strong.html

    ReplyDelete
  6. Taylor AdkinsSeptember 9, 2009 at 7:00 PM

    The structure of an atom:
    http://web.jjay.cuny.edu/~acarpi/NSC/3-atoms.htm

    ReplyDelete
  7. Colby "Girlfraand" MabrySeptember 9, 2009 at 7:40 PM

    http://chemed.chem.purdue.edu/genchem/history/rutherford.html

    Very in depth explaination of Rutherford's "golden foil experiment."

    ReplyDelete
  8. Mr. ScullySeptember 10, 2009 at 11:03 AM

    this website REALLY helped me understand what an atom was. http://www.sciencekidsathome.com/science_topics/whats_in_an_atom.html

    ReplyDelete
  9. Ben SmithSeptember 10, 2009 at 5:13 PM

    http://www.ehow.com/about_4569065_rutherfords-gold-foil-experiment.html

    Good site on rutherford and his experiment

    ReplyDelete
  10. Chris MathewsSeptember 12, 2009 at 10:02 AM

    http://education.jlab.org/qa/particlemass_02.html

    This is a website that will help you to better understand the masses of the subatomic particles inside an atom.

    ReplyDelete

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