LAB RATS.

Fix a Mix of Thix Trix

It flows like water; it sticks like sand. What is it? It's ketchup, for one thing. And it's quicksand, and oil-well drilling mud. All of these things are known as thixotropic (thix-oh-TROPE-ik) solutions. At different times, they can behave like liquids or solids. Want to make some?

YOU NEED:

1 cup of water
1 1/2 cups of cornstarch
A shallow dish
A wooden spoon
Food coloring (any color
or combination)

DIRECTIONS:

1. Place the starch in a bowl and slowly add water (to which you have already added food coloring).

2. Mix well.

AMAZE YOUR FRIENDS!

Your goop will do weird and seemingly unexplainable things:

* Swirl a bowl of thix trix in front of your friends. It will Look Like a Liquid. Then drop a baseball or other hard object into it; they'll jump back, expecting to be splashed. But the "liquid" will stay in the bowl!

* Squeeze a handful of thix trix, then open your hand and the solution will ooze from between your fingers and into the pan.

WHAT'S THE DEAL?

Thixotropic solutions behave oddly because of their molecular structure. Their molecules tend to line up in long chains, which stick together and prevent much movement. When the solution is stirred, the chains are broken and the solution can flow freely, like a Liquid.

Here some other thixotropic solutions:

* Margarine

* Yogurt

* Synovial (sin-OH-vee-ul) fluid--Fluid surrounding your body's joints that cushions them and helps them move more smoothly.

CALLING ALL LAB RATS

Are you a beaker, flask, and Bunsen burner sort of person? Then we want to hear about your favorite science experiment. Send a copy of your own original experiment along with snapshots or drawings of you and your friends (or your class) performing the experiment to: U*S*Kids Lab Rats, P.O. Box 567, Indianapolis, 46206. We'll use as many as we can in the magazine.