What is Oobleck?
If you’ve never had any experience with Cornstarch Slime or Goop (or what I call Oobleck from Dr. Seuss’ book Bartholomew and the Oobleck), it is really strange. If you move slowly or hold it still, it behaves like a liquid. But if you quickly agitate it or attempt to roll it up, it behaves like a solid!
This science experiment certainly isn’t a new one…
In fact, you might have already done this science activity with your kids! It is a great sensory experience for little kids and a way to talk about matter (liquids, solids, and gases) with older kids!
Here’s what you’ll need: cornstarch, water, and a large bowl.
Optional: food coloring.
How To Make Oobleck
1. Mix 1 cup of cornstarch and 1/2 cup of water. It should be the consistency of syrup. Add food coloring if you choose. I opted to leave this out to make the clean-up a little easier (and preserve the boys’ clothing).
2. Encourage your child to put his/her hands in the bowl and begin playing. Big Brother was excited, at first…
…the texture took some getting used to. After a few minutes, he really enjoyed it.
Is Oobleck a solid or a liquid?
Cornstarch, the main ingredient of Goop or Oobleck is made up of long chains of atoms. When you move them slowly past one another, they flow like a liquid because they can slide easily past each other. When you squeeze, roll, or agitate them, the “atom chains” will get entangled and form a solid!
Substances like Oobleck are referred to as “non-Newtonian fluids” because they do not have the normal properties of either solids or liquids.
This post was first published May 2012. Updated 2018.
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