Not enough time on your hands to think of scientific experiments your child can do? Think most science requires esoteric equipment? Actually, most of what you need to conduct meaningful experiments is right in your kitchen. It’s knowing what to do that’s sometimes tough to figure out.
Science is all about discovering how things work and trying to solve problems. Simple, hands-on experiments that begin with, “What do you think will happen?” or end with, “Can you make it happen differently?” get children’s minds in the right place. Even letting children play with the materials before you begin gets them thinking about how the materials work together. Encouraging children to help whenever they can by reading steps, measuring out materials, and cleaning up maximizes their learning experience and investment.
Dancing Grapes is an easy-to-set-up experiment that involves mixing baking soda in water with some vinegar to create carbon dioxide gas. Grapes added to this mixture will sit at the bottom at first; then, as the bubbles collect on the sides of the fruit, they’ll begin to float. When they reach the top, the bubbles on the grapes pop and the grapes sink back down. The cycle will repeat with the grapes going up and down until all the bubbles are gone.
Understanding buoyancy will help your children get the most from the experiment, so here’s a quick explanation: Buoyancy is a measure of how something floats or sinks in a liquid. Rolled up tinfoil sinks in water, but if you make it into the shape of a boat, it floats. You change the density of the tinfoil shape as you make it boat-shaped.
In this experiment, the grapes initially are too dense for the water, but the bubbles help to increase their buoyancy.
You’ll need a tall, clear water glass; water; baking soda; vinegar; grapes; teaspoon; and paper towels.
- Fill a tall, clear glass 3/4 full of water.
- Mix 1 teaspoon of baking soda into the water until it’s nearly clear (dilute the baking soda as needed).
- Put 2 to 3 grapes in the glass.
- Observe how the grapes sit at the bottom and explain how the grapes are denser than the water.
- Ask what will happen when you put vinegar into the baking soda water (this will test to see if your child has any prior knowledge of mixing the two).
- Have your child pour approximately 1/4 cup of vinegar into the glass (put paper towels underneath the glass in case it bubbles over).
- Watch the bubbles gather on the sides of the grapes, then watch them “dance” as they slowly rise and then fall.
This is a simple yet informative and exciting experiment for your kids to do right in your kitchen. They’ll love to see the grapes bobbing up and down. And even if the vinegar and baking soda spills, the mixture can be used as a safe cleaning agent, so just wipe it up.
The experimenting doesn’t have to be over yet, though. In fact, this is when the science really starts to happen. Your kids might ask if this will work with other types of fruit (blueberries, strawberries, or raisins, maybe). They might choose a different glass size, differing amounts of baking soda and vinegar, or more or less water. Whatever they do, it’s in the name of science. By encouraging their experimenting, you’ll be encouraging their scientific minds.
Steve Davala, a father of two, teaches eighth grade science and writes children’s books and parenting articles.