In the last experiment, you learned about surface tension, which allows lightweight objects to float on the surface of water. Can we break that tension? Yes! And by using something you're very familiar with!
Soaps and detergents can actually break apart water's surface skin. Here's an easy experiment to try... First put a drinking glass somewhere that is safe if some water spills. You might want to place the glass on a few sheets of newspaper or some paper towels. Fill the glass of water very, very full with water (an eye dropper will help). When you look at it from the side, you should be able to see that the water surface is actually a little above the top of the glass. The top of the water is curved because of surface tension.
Now take a toothpick and dip one end into some dishwashing soap. Carefully touch the end of the toothpick to the water surface. What happens? Dr. B warned you that there would be a mess! The soap breaks up the close-packed molecules in the water's "skin", so they can no longer support the curved surface.
This is actually a good lead-in to September's topic, which is BUBBLES! You'll be experimenting with soap again!
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