Science Experiments Ideas
Bath game with a coin
Stretch a strip of cellophane not plastic foil, 1 inch wide,tightly over a soup plate and fasten the ends with adhesive tape. Lay on the middle of the strip an average sized coin and pour water into the dish up to about 3 inch under the coin. The coin sinks slowly and reaches the water after several minutes.
The water vaporises, the cellophane absorbs the water particles from the air and expands until it reaches the water. But strangely enough it soon begins to tighten again, and the coin rises again slowly to its original position.