Oh, another idea is Alka-Seltzer rockets. Have you done those? You take an empty plastic film canister--the ones with slightly flattened tops (like from Fuji) work better than the ones that come down over the outer edges of the canister (like from Kodac)--and put 1/4 of an Alka-Seltzer tablet and a small quantity of water into it. Close the lid, shake, and place the closed canister, top-side down, on the ground. The fizzing tablet will build up gas pressure inside the canister until the canister shoots up into the air, leaving the top (and a small puddle, so be prepared) on the ground. Very impressive!
Could you send home a booklet or sheet of ideas for experiments to try at home? I'm not sure where you'd find one premade, but you perhaps could compile your own. Perhaps could include a baggie of supplies for one of the experiments--like bits of styrofoam for experimenting with static electricity.
You could get great project ideas from those Wild Goose brand Test Tube Science kits, or from some of those books of science fair ideas.
One of my kids' favorite projects involves a see-through container, like a babyfood jar, into which you pour a little water, a few drops of food coloring, and a little cooking oil. Shake it up, and the food coloring blends into the water but not the oil, and the (now colored) water and oil separate into two distinct layers. Then add a penny, a grape and a styrofoam peanut. The penny sinks to the bottom, the styrofoam floats on the top, and the grape hangs between the oil and water. Very cool, and leads to great discussion of the properties of liquids and solids. It's fun to let the kids who haven't done this before try to predict what the results of each step will be.
