Tuesday, November 17, 2009

11/17/09 The nucleus

This week we talked about atomic structure. Specifically, we discussed Lewis dot diagrams, electron energy levels, orbitals, ground and excited states, the EM spectrum and properties of waves.

The Rutherford's experiment and the Isotopes of Kandium lab reports were collected.

We did the Spectroscopy lab. This report is due on Wednesday, 11/18.

We will have a test on Friday, 11/20.

Coming up
  • We will do the Flame test lab.
  • We will begin the Nucleus unit. The material from this unit will not be on the test this Friday.

Students need to complete one project each month. The current project is the first of two choices. If both are completed, it will count as extra credit. Click here to see the project.

Info from the page of the graphic for this entry: The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks. In nuclei with many nucleons, the effective strong forces may be described by the exchange of mesons (particles composed of quark-antiquark pairs). A proton consists of two up quarks and one down quark along with short-lived constituents of the strong force field. A neutron is similar except that it has two down quarks and one up quark. Although scientists are convinced that nucleons are composed of quarks, a single quark has never been isolated experimentally. Energy brought into a nucleus to try to separate quarks increases the force between them. At high enough energy, the addition of energy creates new particles rather than freeing the quarks.