One of my goals with these science videos is to provide support to the homeschool community. After years of writing the Experiment of the Week, and presenting science shows for homeschool groups, I have been impressed with how strongly homeschool families are involved with hands-on science. I have also seen the need for a science curriculum that fulfills their educational needs. Starting with these videos, I hope to offer the homeschool community some of the science education support that they need, as well as a fun way to get students involved with scientific discovery.
I also try to use activities that involve common items. Most homeschoolers don't have access to test tubes, flasks, chemicals, microscopes and other scientific equipment. In the future, I hope to be able to guide them to inexpensive sources for science equipment to enrich their science curriculum.
Most people have at one time or another rubbed a balloon on their hair and then let it stick to their head or to the wall. You might have even used the static charge on the balloon to attract bits of string and paper. Now we will see that these static charges can even attract liquids, such as water.
For this experiment you will need:
- a balloon
- a water faucet
- possibly a hair drier
Blow up the balloon. Use the cheapest balloon that you can find, as these are usually made of thinner rubber, and seem to generate more static charge. Turn on the faucet until you have a very thin stream of water flowing. Now rub the balloon on your hair or on a piece of cloth. You can test to see whether you have a good static charge by holding the balloon near the back of your hand. If you feel the hair on your hand move, then the balloon is charged. If you have trouble getting the balloon charged, dry both the balloon and your hair with a hair drier and try again.
Once the balloon is charged, bring it near the stream of water from the faucet. You will see the stream of water bend towards the balloon, and if you bring the balloon close enough, tiny drops of water will break free and leap to the balloon.
What is happening? Static charges are very similar to magnetic charges. As with magnets, two objects with like charges will push apart, while two objects with different charges will attract each other. When you rub the balloon on your hair, the balloon picks up electrons from your hair and that gives it a negative static charge. As you bring the negatively charged balloon near the stream of water, electrons from the side of the stream closest to the balloon are pushed away, leaving behind a positive charge. The positively charged water in the stream is attracted to the negatively charged balloon, and the stream bends towards the balloon.
If the balloon gets wet, you will probably have to dry the balloon with a hair drier before you can get the experiment to work again. Humidity makes it difficult to get static charges to stay where they are generated. The charge drains away across humid surfaces.
Have a wonder-filled week.
