This is a great little experiment! You'll see the sound making the grains of rice move and jump so much! You will need: A big bowl, cling film, uncooked grains of rice (or rainbow sprinkles), a metal pan and a metal spoon.
Pull the cling film tightly over the bowl. (One piece, as tight as you can get it, without it breaking.) Put about 1 teaspoon of rice (or sprinkles) on the plastic. Hold the metal pan close to the bowl (without touching) and have your child hit it with the spoon - the harder they hit it the better. The rice will dance!
What is happening?
The pan vibrates, creating a sound wave. This wave is transmitted through the air and causes the plastic wrap to start vibrating as well, making the rice dance! You are seeing the result of the sound waves in the rice.
Are any patterns formed? Try hitting the pan harder and then more gently. How does the behavior of the rice change? See if your child can hit the pan hard enough to bounce the rice right off the plastic! Enjoy!