This Week's Experiment - #464 Oil and Water and Static, Oh My!

This week's experiment is one that I came across while researching for the science videos. I came across an article that compared the effect of static fields on polar and nonpolar materials. Sound complicated? Really, it is simple and amazing. To try this, you will need:

a balloon
water
oil
syrup

We will start with something that we have done before. Blow up a balloon and tie it off. Then rub it against your hair or a piece of cloth, to build up a static charge. If you bring the balloon near the back of your hand, you should feel the hair standing up on your hand.

Then turn on the water in your sink. Turn the water down to form a very thin stream of water. Bring the balloon near the stream of water, and you should see that it bends towards the balloon. You may even see drops leap from the stream to the balloon.

Now come the new part. We want to try the same thing with a thin stream of oil. I put a bowl in the sink and then poured cooking oil into it, trying to get a nice, thin stream like I had with the water. This time, when I brought the balloon near the stream, it did not bend or react to the static charge. Why?

Well, the article that I read said that it was because water is polar and oil is nonpolar. What in the world does that mean? No, it doesn't mean that you don't find oil at the North Pole. If a molecule is polar, then one part of the molecule will have a positive charge and another part will have a negative charge. Nonpolar molecules have a neutral charge all over. That should mean that the polar molecules will be pushed or pulled by the electrostatic charge on our balloon.

OK, so it seemed to work, but I was wondering if part of this was because the oil was thicker than the water. To test that, I did the experiment again, using some sorghum molasses (a thick syrup popular in the Southern United States). Since it is water based, it is also a polar liquid. Instead of pouring it into the sink, I poured a thin stream onto some nicely buttered toast. The charge of the balloon did the same thing to the syrup that it did for the water, showing me that even thick liquids are bent by the static charge. It also made a nice, tasty design on my toast.

That lead me to wondering if the same thing applied to solids. Wax is a nonpolar solid, while wood is polar. If solids react in the same way as liquids, then you should be able to sort a pile of tiny bits of wax and wood by bringing the balloon near the pile. Does it work? <grin> Guess you'll have to try it to see. Why should I have all the fun?

Have a wonder filled week.