Puffed cereal grains are great materials or science experiments. Since they are light in weight, they do not require much force to move. In addition, the puffs easily transfer electric charges. Do you want to see? Just try this next experiment.
Things Required:
Puffed cereal grains
Balloon
A piece of wool or fur
Directions:
Stuff about a dozen grains of puffed cereal into a balloon. Inflate the balloon.
Rub the balloon with a piece of wool or fur. If the material isn’t available, you can rub the balloon against your hair.
Hold the hanging balloon by its knot. Observe the grains within the balloon. Are they stationary or moving? Touch the balloon with the fingertips of your other hand. How do the grains behave? If nothing happens, recharge the balloon by giving it twice as many strokes. Then, touch it again.
This Is What Happens:
As the balloon rubbed against the wool, it became negatively charged. Its negative field induced a positive charge in the nearby side of the puffed grains. This positive region was attracted to the balloon, causing the grains to cling to the negative skin of the balloon.
When you touched the balloon with your fingertips, things changed. The negative charges of the balloon drained out through your fingers. This created a positive region in the balloon. The charges in the grains could not shift fast enough. Instead, the positive grain surface and the positive balloon skin repelled each other. The grains jumped to another location.
