The Bouncing Egg

Can an egg bounce without breaking?

You will need:  2 eggs, water, vinegar, 2 glasses, flashlight, bowl

1. Put one whole egg in a glass of water and the other whole egg in a glass of vinegar.
2. After several hours look at both eggs. Do they still look the same? The egg in water is the same, but the egg in the vinegar has changed. The shell has begun to fizz. The acid in the vinegar dissolves the calcium carbonate that's in the shell.
3. Leave both eggs alone for 7 days. After that time take the egg in vinegar to a dark room and shine a flashlight at it. The light bounces off the egg!
4. Take the egg out of the glass of vinegar. Hold the egg over the bowl and let it drop!

What Happens: Your egg bounces! Try it again a little higher each time. See how high you can make the egg bounce. Then hold the egg in water over the bowl and let it drop.

Why:  A chemical change takes place in the egg when left in vinegar.  The vinegar, which is an acid, reacts with the calcium carbonate of the eggshell.  The change makes the shell go soft, then disappear. This is called "decalcification."  The egg in the glass of water does not chemically change.