Oobleck is a classic experiment for a reason: it’s messy, it’s easy, it’s entertaining, and it’s scientifically fascinating. What makes it so interesting? Mix some up for yourself and see if you can figure out why!
To make oobleck, you’ll need:
-cornstarch
-water
-a bowl for mixing
-tablecloths to catch the mess
-tablespoons
To get measure out the ingredients for oobleck, we recommend starting with 1.5 tablespoons of corn starch and 1 tablespoon of water. The ratio should be able 1.5-2 parts corn starch to one part water.
Mix well, stirring all the corn starch into the water.
As you stir, explore what this new substance is doing. What happens when you press on it? What happens when you pick some up and let it drip into your bowl?
Oobleck is known as a non-Newtonian fluid. Newton said that the viscosity (thickness or ability to flow) of a liquid can only change when there’s a change in temperature. Think about water and ice. Oobleck doesn’t follow this rule! If you touch it fast, it will feel like a solid, but if you touch it slowly, it will feel like a liquid!
Why? This is because the corn starch doesn’t dissolve into the water! When the oobleck is pressed together, it pushes the corn starch particles against each other, making it feel like a solid. When pressure is released, the water molecules fill the space between the corn starch particles, making it turn runny again.
Can you shape your oobleck into a ball? What happens when you release the ball?
If it’s warm enough outside, try taking it outside for a game of catch! Move quickly, though, since it starts to “melt” as soon as pressure is released!
Note for parents: Do not put down sink; dispose in the trash.
