Making Eggs That Bounce
Grade Levels: 3 - 8
Did you ever try to bounce an egg? Don't! Not until you read through this experiment, anyway.
This experiment is more fun if you do it with a couple of friends, because you can have a bouncing egg contest when you've finished it. So round up a couple of pals, a dozen eggs or so, and let's get started.
As you know, eggs have shells that you must remove before eating.
If you put eggs in their shells into vinegar, however, the vinegar will do the work of removing the shell for you. That's right. The vinegar will dissolve the eggshell. This happens because vinegar contains an acid called acetic acid, which reacts with the high calcium content of the eggshell. Be sure to completely cover the egg with vinegar so that the entire shell dissolves. If there are any pieces of shell left, the eggs won't bounce.
It takes three or four days for the shell to dissolve completely, and you must wait until all the shell is gone before trying to bounce the egg.
All you need to do is put some raw chicken eggs into clear, plastic cups. One egg to a cup, please. This allows you to watch the reaction as it occurs. Completely cover each egg with vinegar, and let them sit in a place where they don't have to be moved.
Check the eggs now and then over the next four days, noting any changes that you see in the shells.
After four days, very carefully, using plastic spoons, remove the eggs from the cups and lay them onto a couple layers of paper towels in order to drain. You'll notice a waxy looking coating on the eggs, but no more shell.
Starting at about 2 inches high, drop an egg onto a tabletop or other surface, and watch it bounce. Working in increments of 1 inch, drop the egg from increasing elevations, having your friends do the same if you conducted this experiment with others.
Whoever has the egg that survives a drop from the highest height, wins.
Don't forget to record your observations as you drop the egg, noting drop heights and how the egg reacts to each drop.
Excerpted from The Complete Idiot's Guide to Science Fair Projects © 2003 by Nancy K. O'Leary and Susan Shelly. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.
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