Here’s a fun, easy science project that I discovered a few years ago on pbskids.org/dragonflytv. My children will do it again and again. Even my three year-old joined in, cutting up construction paper into “fish food” and throwing it into the water.
You will need some sort of pan for water (a cake pan will work), construction paper, scissors, and dish soap. Have your child cut out some fish shapes from the paper (around two inches long works well.) See the photo below. Then, have them cut a small slit in the back of the tail. Put a few inches of water in the pan and add the fish. Before the paper soaks up too much water, have your child add a drop of dish soap behind the fish. The fish should zoom across the water. You will have to add fresh water tothe pan if you want to repeat the experiment.
The soap breaks the surface tension of the water. Tell your child to imagine that the surface of the water is a sheet of fabric and the soap is a pair of scissors. The soap cuts through the water, pushing the fish ahead of it. For a more scientific explanation, have your child look up surface tension or visit the dragonfly tv website!
Don’t forget those science notebooks! Have your children write the date, “surface tension” and record their results. They can try using different liquids (like lemon juice) to see if they will break the surface tension. My kids made some fish out of that foam that is used for craft projects so that they wouldn’t soak up the water! Hopefully, the zooming fish will keep your child interested and busy for a while! Click here to see a video on how to make zooming fish.