This experiment shows how things float more easily in saltwater than in freshwater. For this experiment, you need an egg, a large glass, water, table salt and a tablespoon. Begin by placing the egg in the large glass. Fill the glass with water; the egg should remain on the bottom of the glass. Add salt, one tablespoon at a time, until the egg begins to lift off the bottom of the glass. Continue adding salt until the egg rises to the top of the glass, floating on top of the water.
This experiment demonstrates the attractive power of static electricity. The only materials required for this experiment are balloons and the participants' clothing and hair, making it very easy to perform without much preparation. Give a balloon to each person and have them blow it up. Each person should tie off his balloon, then rub it on his hair. Explain that this action gives the balloons a negative charge and they will now be attracted to things with a positive charge. Have the participants stick the balloon to their shirts, the wall or one another.
For this experiment, you need two cans, about 3 feet of string and two paper clips. Poke a hole in the bottom of each can. If you are using metal cans, you may have to use a hammer and a nail to punch through the metal. Push one end of the string through the hole and pull it through a few inches. Tie the end to a paper clip, then pull the string so the paper clip is against the bottom of the inside of the can. Repeat this process for the other can.
Have two children each hold a can and take turns speaking into it. The person at the other end of the string should be able to hear the other speaking because of the vibrations sent along the string.
For this experiment, you need a balloon, a funnel, an empty glass or plastic bottle, baking soda, water and vinegar. Fill the bottle with 1/4 cup vinegar and 1/4 cup water. Use a funnel to fill the balloon half-full of baking soda. Stretch the opening of the balloon over the mouth of the bottle, being careful not to spill any of the baking soda into the bottle. While holding the balloon firmly on the mouth of the bottle, empty the baking soda into the bottle. There will be a chemical reaction between the vinegar and the baking soda, causing excess gas to be produced, inflating the balloon. This allows children to observe chemical reactions and the effects of air pressure.