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Strange acting goop

Ever had a hot, steaming cup of Oobleckh? Geez, I hope not. The stuff is nasty! But it does exhibit some interesting properties...

1. Put one and one half (1 1/2) cup of cornstarch into the bowl.
2. Add one cup of water.
3. Mix well.

Slowly dip your finger into the gooey mixture. Feels liquidy? Grab some in your hand and pour it back into the bowl. Now, try slapping it hard with your hand or a heavy spoon. What happens? Why?

The molecules in ooblekh are very large compared to, for instance, molecules of water. When slapped quickly, they tangle themselves up preventing any splattering. In this way the mixture behaves more like a solid.  When you slowly poke your finger into the mixture it easily slides right through.  In this way the mixture behaves more like a liquid.

Supplies: Corn starch