Shirley Hatcher (Williams School)
Chocolate Chip Diamonds
Everybody started with #19 paper clips and toothpicks to remove chocolate chips from cookies within a five minute period. We had to "pay" for the tools, but got "money" back for each chip ["diamonds", from a diamond mine]. We then filled out a Cookie Mining Worksheet that contained the following questions:

• Starting Capital $19.00
• Cookie Cost [$3.00]
• Equipment Cost [flat toothpicks, round toothpicks, paper clips, total]
• Remaining Capital [must be zero or greater]
• Cost of mining ore [$1.00 per minute]
• Reclamation cost [$1.00 per square]
• Total Mining Cost
• Value of ore (chips) [$3.00 per chip]
• How much did I make? [remaining capital plus value of ore]
• Total cost
• Loan Repayment
• Profit (Loss)

Glenda Ellis (Williams School)
Clouds
She put about 22 oz of water in a 2 liter plastic bottle, shook it for about 20 seconds, and then dropped a lighted match inside, and squeezed the bottle intermittently to see cloud formation. First she did it with cold water, and then tried it with hot water, which produced a more visible cloud.

Beverly Merchant (Soujourne of Truth School)
Diffusion
[a]: Sprinkle pepper in a glass of water, and then rub a wet finger on a bar of soap, and touch it to the center of the water surface. The pepper is pushed to the edge of the class. Why?
[b]: Milk streamers. Put milk into a cup, and add several drops of vegetable dye near the edge. Add liquid dishwashing soap [Joy], and notice that the dye moves around. Why?

Erma Lee (Williams School)
Bouncing Buttons and Bouncing Raisins
Add raisins to a glass of water, and to a glass of soda water. Notice what happens.

Then, put on safety goggles, and put buttons in a jar with vinegar. Add baking soda to the jar, and notice that the buttons bounce. Why?

Camille Gales (Coles School)
Math Activity on Classification
This activity, which involves classifying 4 brands of raisins, can easily be extended from lower to higher grades by being more quantitative and requiring a more sophisticated approach. The following questions were considered:

• Cost of box?
• Weight of box?
• Average Number of Raisins in box?
• Average Weight per raisin?
• Average Cost per raisin?
• Brand that has best value?
• Other factors that might influence choice?

Charlene K Smith (Wirth School)
Worms
Charlene did a series of presentations that are described in the book Worms Eat Our Garbage by Appelhof, Fenton, and Harris [1995] ISBN 0-942256-05-0. In particular, we did the following exercises:

• Having an Attitude [about worms] Five Minute Date. [work sheet]
• Can you Prove IT? [facts and opinions] Five Minute Date [work sheet]
• Floaters:Why do earthworms surface during a rainstorm? [worms in a jar with dirt and gravel at bottom. Add water; worms surface, because of lack of oxygen in saturated ground.]
• Heads or Tails Put fingernail polish remover on a tray, and put a worm nearby. The worm moves over [head first] to the location, and then draws back. The worm can smell the chemical, but does not like its taste. Worms do not have eyes, but can feel the light, and know to go underground.
• Observation Chart Worms eat food scraps, as you can see in your own worm farm. Worms can be gotten from a "bait shop" for fishermen.
• The Worm's Body Quiz
• Paper shredding Event Make a home for worms.
• Certificates of Recognition for Worm Farming

Therese Donatello (ST Edwards School)
Soap Bubbles
She had a container filled with soapy water, for making soap bubbles. We got some of the fluid in a paper cup, and made our own bubbles by blowing on a swizzle straw. We saw the pattern of reflected light on the bubbles, which contained various colors, and which changed with time. The top was reddish and the bottom greenish; then the top became clear just before the bubble burst. Why?

The bubbles illustrated the concept of constructive or destructive interference with thin films. For constructive interference, the peaks line up, but for destructive interference the peaks and valleys. One can see similar effects with oil on water [oil slicks on roads or sidewalks]. She showed a scale model with paper "wave trains" to illustrate the effect.

Therese also pointed out that the diffraction pattern on the back of a CD is caused by the grooves on the compact disk, which serve as a diffraction grating for incident light. The effect here is diffraction, rather than interference.

Ed Scanlon (Morgan Park HS)
Human Muscle System
He wore a "muscle shirt", and brought a "skeleton shirt" that was stylishly modeled by Carl Martikean. Ed had prepared models for muscles out of red cloth, with VELCRO^TM for attachment to the "muscle shirt" in the right place. He explained that muscles work by contraction. He named the muscles, attached the models to the shirt/body, and illustrated how the various muscles are exercised. He considered these 7 muscles:

Ernest Garrison (Jones Commerical HS)
Polyethylene Foam
He produced polyethylene foam by mixing parts A and B in a styrofoam cup, which was then stirred by his trusty assistant. It turned into a yellow liquid, which began to expand and become slightly warm after a minute or so. The porous yellow substance is widely used for "retrofit" insulation in old houses. It expands to several times its original volume, and the trapped air bubbles make it a good thermal insulator.