Winter weather means it is time for one of my most favorite science activities – ALL THINGS STATIC ELECTRICITY! What causes static electricity to be so prevalent in the winter months? It is primarily based on two facts: wintertime is typically drier than summer, when the air is more humid. Electricity needs the dry air in order to hold the charge. And, we tend to wear things (such as wool hats and scarves, jackets and socks) that increase the presence of static electricity.
Without bogging down on how static electricity is formed, it simply needs two “insulators” to rub together. Insulators are things made of plastic, cloth, or glass. These can hold charged atoms, called ions. When they come into contact with a “conductor”, such as metal, the energy is transferred (and we get a shock!). Here are some great things to try on a cold, dry day to experiment with static electricity.
- Take a piece of dry cereal, such as an “O” shaped cereal, and tie it to a thread about a foot long. Tape the thread on the side of a table so that the cereal hangs loosely without touching anything. Next take a clean, dry comb and rub it on a sweater or comb through dry hair. Now, hold the comb close to the cereal. What does the cereal do? When the cereal is hanging loose again, recharge the comb and place it near the cereal again. Are the results the same or different? Why?
- Rub a dry, clean comb on a sweater or through dry hair and hold it near a running faucet (run the faucet in a slow, steady stream, not full-blast). Watch what happens to the stream of water.
- This is my favorite, but it definitely requires an adult to do it. Take a fluorescent light bulb into a dark room. Rub a dry, clean comb on a sweater or through dry hair (do this a lot to build up a good charge). Touch the comb to the light bulb and see what happens. Try touching the light bulb in different places and see if the results change.
These experiments can be done with balloons that are blown up and tied as well. Try it both ways and see which way works best!