Water Surface Tension Experiment
Instructions:
Watch the black pepper scatter as you break down the water surface tension using soap.
Materials:
cereal bowl
water
ground black pepper
liquid soap
a toothpick
Directions:
Fill a bowl with water
Shake the black pepper onto the surface of the water (Notice how it stays afloat on the water? That is the surface tension holding the layer up)
Take a toothpick and put the end into soap so that it coats the end
Gently touch the surface of the water with the toothpick
Did you see how the pepper shoots back in all directions? What must the soap be doing to the surface tension?
Soap is something that actually breaks down the cohesive powers of water, making it have less surface tension.
If you mix some soap with water and make a water droplet on your counter again, what do you think the shape would look like? Give it a try!