If your kids haven’t done the cornstarch and water science experiment, they are missing out on a lesson that is fun and educational!
This cornstarch and water experiment is a great way to teach the States of Matter and non-Newtonian fluids. Is it a liquid or solid? YOU decide! You can pick it up like a solid, but it will run through your fingers like a liquid – it is unlike anything you’ve felt before! This experiment can be a bit messy, but couldn’t be easier to create and it will provide an entire afternoon of fun!
Here is a video my kids and I made doing this cornstarch and water experiment, but keep reading for detailed directions and scientific applications:
Cornstarch and Water Experiment
What You Need:
- Cornstarch (about 1 cups)
- Water (about 1/2 cup)
- Bowl or Pan
You Might Also Need…
- Newspaper (to cover your experiment area)
- Food Coloring (if you want to make it colorful)
- Small plastic toy
You can use this experiment in conjunction with the Dr. Suess book “Bartholomew and the Oobleck”. Just add some green food coloring to your mixture and have fun!
Cornstarch and Water Recipe
- Mix the cornstarch with water in your bowl. Add more or less of each ingredient until you get the consistency of honey.
- Play with it!
- Tap the surface with a spoon- does it splash?
- Grab a handful and watch it slip through your fingers.
- Grab another handful and squeeze it. Does it slip through?
- Let your fingers slip slowly down to the bottom of the bowl. Try to pull them out fast!
- Grab a handful and roll it in your hands to make a ball. Stop rolling and watch what happens!
- Place a small plastic toy on the surface- does it sink?
- Stir the mixture slowly with your finger- do you feel resistance?
- Now, stir the mixture quickly with your finger – do you feel resistance now?
Cornstarch and Water Science Experiment Explanation
In the 1700’s, Isaac Newton identified the properties of a liquid. Water, juice, and other liquids have those properties and are called Newtonian Fluids. The cornstarch and water mixture has properties of both a liquid and a solid, so it is identified as a non-Newtonian fluid.
This mixture is made up of solid particles suspended in water. Chemists call this type of mixture a colloid. Colloids behave differently than solids and liquids. It can act like a solid when you apply force, but acts like a liquid when it isn’t under pressure.
Can you name any other non-Newtonian fluids? Ketchup and quick sand are both non-Newtonian fluids.
Next time you need to get some stubborn ketchup out of a bottle, don’t smack it – that will actually slow it down. All you need to do to get it out is to tip it over and have some patience.
And if you ever find yourself in quick sand, don’t panic and try to get out quickly! Move slowly, because the less force you apply, the less the quicksand will resist your movement.
Leave us a comment below if you try this cornstarch and water experiment and let us know how it goes. HAVE FUN EXPERIMENTING!!