Walter Kondratko [Steinmetz HS, chemistry] Spectrums
and Colors (Handout)
Walter had several tubes filled with various gases (one gas per tube: hydrogen, helium, mercury, etc.). The tubes can be charged with an electric current, the energy from which will excite the atoms. When the atoms return to their ground state, they will release energy in the form of photons (colors). The energies (colors) in each case are characteristic of each element, and can be distinguished using a small diffraction grating. White light (the control lamp) gives a complete continuous visible spectrum:
We then looked at the white light again, but through solutions of various chemicals (Potassium Permanganate-- KMn04, etc.) The absorption of characteristic wavelengths of light by each chemical will cause the (previously) continuous spectrum to be missing certain colors. Each solution resulted in a characteristic pattern of colors being absent from the spectrum.
Walter received this equipment on loan because he participated in the ChemVan program at Chicago State University.
This was a terrific activity, which everybody thoroughly enjoyed!
Chris Etapa [Gunsaulus Academy]
Mutations and Variation
Chris distributed a handout obtained from the Museum of Science and Industry -- written by Melanie Wojtulewicz.
We didn’t have time to do all the activities, all of which involve genetics and DNA, but did talk briefly about the Punnett square analysis with Sickle Cells, isolation of DNA from peas, cloning of Dolly the Sheep, and the activity illustrating the various types of mutations. What we did today was to make a model of DNA using pipe cleaners, longer continuous pieces for the “sides” of the “DNA ladder” (the “sugar-phosphate” backbone), shorter pieces for each “rung” (“base pair”) of the ladder and colored beads, strung two on each rung, for the bases (one color for each base). We made sure that for each base pair the appropriate colors (bases) were paired with each other:
Another great learning activity!
Mary Lucy Adetunji [Gale Elementary School] The Five Senses
Sister Mary had us do activities that she uses with her kindergarten students. These activities were interesting to us; we learned how observational science can be taught to students at an early age.
Notes prepared by Benjamin Stark.