Ever wonder how something can behave like a liquid or a solid depending on how much pressure you apply? Oobleck is a non-Newtonian fluid that behaves just like that, let’s explore it!
My kids love playing with slime! But before they played with slime we played with Oobleck. The great thing about Oobleck is that we learned so much about non-Newtonian fluids. Oobleck is a suspension of cornstarch and water that can behave like a solid or a liquid depending on how much pressure you apply. Materials that behave this way are classified as non-Newtonian fluid because their flow properties are not described by a constant viscosity. It is so much fun to play with and so easy and simple. Before we jump into the oobleck experiment, please take a moment to pin this post to your homeschool science board.
Check out the Oobleck Experiment in action!
In this experiment we use cornstarch, if you saw the video then you heard that cornstarch is a white powder made from corn. In cooking, the usual job of cornstarch is to make a liquid mixture thicker, so cornstarch is a common ingredient in recipes for sauces, puddings, and gravies.
In your journal, you should write down what you predict will happen if the cornstarch is mixed with water? When you complete the experiment, make sure to check your prediction and write down any observations and draw a picture.
What you will need:
- 1 cup of cornstarch
- 1/2 cup of water
- Liquid Food Coloring
- Mixing Bowl
- Pens and crayons
Result timing: 5 minutes
What to do:
- First, pour one cup of cornstarch into the bowl.
- Then slowly pour 1/2 cup of water into the bowl.
- Next, add a few drops of food coloring to the mixture.
- Then use your hands to squish the water and cornstarch together.
This experiment works best if you use your hands so don’t be tempted to be neat and use a spoon.
How The Oobleck Experiment Works
The particles of cornstarch are too large to dissolve in the water. Instead, as you mix the cornstarch with the water, slimy strings of oobleck form. The oobleck is an example of a colloid, a special kind of mixture in which particles of one type of material are suspended in a different kind of material. The particles are so small that you may not be able to see that they are separate from the liquid or gas in which they are floating unless you can look at the mixture under a microscope.