Try This at Home: Bending Water
Illustrated Concepts
Opposite charges attract each other and like charges repel each other.
What You Need
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faucet with running water
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1 balloon
hair
What To Do
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Make sure you have an adult with you to supervise this experiment.
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Blow up the balloon and tie off the end. Rub the balloon on your hair for about 20 seconds.
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Turn on the faucet so that only a small stream of water is coming out.
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Make a hypothesis! What do you think will happen when you hold the balloon close to the water? Why?
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After you rub the balloon on your hair do not let the balloon touch anything else. Hold the balloon close to the running water (but not in the water). What do you notice the water doing? Touch the balloon to the ground or to the edge of the sink and then hold it close to the water again. Does the water behave differently?
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Clean up.
What's Happening
As you rub the balloon on your hair, it is stripping negatively charged electrons from your hair. The added electrons give the balloon an overall negative charge. When you hold the balloon close to the water, the balloon attracts the positive charges in the water and repels the negative charges in the water (water is overall neutral). The attraction of the charges is a stronger force than the repelling of the charges. Therefore, the water bends toward the balloon. When you touch the balloon to the ground or sink, the extra negative electrons from your hair are discharged so that the balloon has equal amounts of positive and negative charge. When the balloon has a neutral charge, the water is not attracted to it.
Fun Fact
The average lightning bolt could light a 100 watt light bulb for 3 months.