Pat Riley (Lincoln Park HS) did the Flame Test. Each of five porcelain evaporation dishes (about 50 ml Pyrex™ beakers may be used instead) contained an aqueous solution of one of these salts
NaCl KCl CuCl2 SrCl2 Unknown Chloride
She added some methanol to each, and with the shades down and lights off, Pat lighted each dish. As the methanol burned, it heated up a bit of the salt in each dish, resulting in a different colored flame for each; The display was beautiful! The color of each is characteristic of the cation (metal ion), the only element differing among the dishes (because all are chloride salts). The heat excited electrons of each cation; the return of the electrons to their ground states was of characteristic quantum, and thus color. The chloride electrons relax with a quantum that is an energy and wavelength that is not in the visible range.
Pat then passed out goggles which diffracted white light. With the goggles on we looked at white light and saw a complete and continuous rainbow of color. Then Pat turned on a red neon light. With goggles on the red light gave us a line spectrum, with only certain colors of the rainbow visible (red, green, yellow, purple) as colored lines, and darkness between the lines. The lines have colors (wavelengths) characteristic of electron energy changes in the neon ions and the quanta emitted corresponding to those changes.
This was repeated with argon light which looked lavender without goggles. With goggles there were blue lines and a few others, ie, a different line spectrum from neon.
This was an absolutely outstanding mini-teach! See also the SMILE presentation by Theresa Fichera [Frazier School] http://www.iit.edu/~smile/ch9105.html.
Zoris Soderberg (Webster School)
shared the lesson she gives her students about the heart. A resource is
American Heart Association
7320 Greenville Ave
Dallas, TX 75231
This is a lesson that "fits" in around Valentine's Day (14 February). She gives facts about the heart, and even brings in a real heart for kids to see - beef or pork - and cooks it for them. Now for us, she first had us feel our pulse, at the wrist, or in neck under side of chin, or back of the leg by Achilles tendon, or in chest. Next, we listened to our hearts with a stethoscope. Zoris got her stethoscope free, from the above address! Lastly, using an electronic device, Pocket Dop II, which amplifies sound, all of us could hear clearly the sound of a volunteer's heartbeat! Cool!
Val Williams (Bass School)
appropriately near Halloween season, set up a full-size plastic replica of a human skeleton, and posed the question, "Why do we have a skeleton?" Ideas we put forth: support; shape; protection; movement; makes blood cells. Val pointed out that 10% of body weight lies in the skeleton. He brings math into the lesson by asking students to calculate the weight of their skeleton from their actual body weight. He then used lyrics from the old song: "The toe bone connected to the foot bone, the foot bone connected to the..." to get kids thinking about how the bones of the skeleton are actually connected together. Next, he projected an image of the skeleton onto the ceiling to get our attention, and played
Dem Bones, Dem Bones, Dem Dry Bones ...
illustrating the connections of the song by pointing to them on the plastic skeleton. This was really fun, as well as informative!
Karlene Joseph (Lane Tech HS)
did Out of Order Hands with us. She had us cross our wrists and fingers. A partner then pointed to a finger, and we tried to move it. There is confusion in our mind because of the "inversion" of limbs, and it's hard to figure out which one to move. In order to move the chosen finger, you must think about it first, and then move the finger you think is on the opposite side of the one pointed at. Then it works!
Next, she had us stretch out both arms, make fists, and press fists together as hard as possible. A partner then presses sideways on both fists with just his index fingers, and can push our fists apart! Why does this happen? Try it and see!
Last, Karlene showed us the glued finger. We placed our hand on the desk with the first 2 joints of the middle finger tucked under our hand and pressed against the desk surface. Now - she told us to try to lift the other three fingers of that hand. But our ring finger would not move! Try it! The bone and tissue structure of the middle and ring finger are connected, so if one cannot be moved, neither can the other. How could you verify this?
Good stuff, Karlene!
A meeting full of wonderful ideas!
SEE YOU NEXT TIME!
Notes by Ben Stark