In this activity, students will have trouble deciding whether this stuff is liquid or solid!

Caution: Do not dispose of oobleck down the drain! Use a trash can.

Materials Needed

Per 2 Students:

1 cup of water
Bowl
Spoon
1.5 to 2 cups of cornstarch

Optional:

A few drops of food coloring
Drop cloth, if working in a carpeted area

Steps:

Pour the water into a bowl.
Add cornstarch a little at a time, mixing thoroughly with a spoon (and then hands, when it gets thicker). When it gets to a nice gooey consistency, stop adding cornstarch (it should crumble when pinched, but ooze when you pick it up with your finger).
Add a few drops of food coloring, if desired, and mix thoroughly by hand.
Squeeze it. Squish it. Pat it. Make it into a ball, then let it ooze through your fingers. It’s a liquid! No, it’s a solid! No- what on earth is it?

Explanation:

This mixture of cornstarch and water is what we call a suspension. That is when one part of the mixture is finely dispersed throughout the other. In this case, the cornstarch particles are floating in the water. When you apply force to the oobleck, the cornstarch particles are forced to get really close together and force the water out. This makes it act solid. When you relieve the force, the particles spread back out and it acts like liquid.

The answer to the confusing question is that oobleck is a solid suspended in a liquid! It is referred to as a Non-Newtonian Fluid.

Try it!

See if you can build something before it oozes away!

Can you get your hand on the bottom of the bowl.

Real World:

This mixture acts just like quicksand, but instead of cornstarch there is sand! It is a dangerous, ooey, gooey, mess!