Eggs
Water
Vinegar
Flashlight
A bowl
1. Put 1 whole raw egg in a glass of water
2. Put 1 whole raw egg in a glass of vinegar
3. The eggs are the same, aren't they? Now, leave them for a few hours.
4. Look at both eggs. Do they still look the same? The egg in the 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 is in the shell.
5. Look carefully. Does the egg in vinegar still have its shell? Touch it. It no feels and looks like a rubber ball, doesn't it?
6. Leave both eggs alone for 7 days. After that time, take the egg in the vinegar to a dark room and shine a flashlight at it. What do you see? The light bounces off the egg, doesn't it?
7. Take the egg out of the glass of vinegar. Hold the egg a little bit over a bowl.
8. Let the egg drop. Do you think it will splatter? Try it.
What happens:
Your egg bounces! Try it again getting a little higher each time. See how high you can make the egg bounce. What do you think will happen if you try to bounce the egg that was in the water? Hold it over the bowl and try.
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.
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