Did you know that you can separate salt and pepper with static electricity? It works because pepper is lighter than salt, so while both salt and pepper are attracted to a statically charged object, only the lighter pepper jumps out.
Static electricity is the buildup of electrical charge on the surface of an object. It is created when objects rub or separate. Positive charges accumulate on the surface of one object and negative charges accumulate on the other.
How to separate salt and pepper with static electricity
You will need to
Salt
Pepper
Bowl
Plastic balloon/spoon or PVC pipe
wool clothing
Instructions
Mix one teaspoon of salt and one teaspoon of pepper in a small bowl.
Blow up the balloon and rub it for about 30 seconds on a woolen item or your hair.
Hold the balloon over the bowl of salt and pepper. Only the pepper will jump to the balloon. If you listen closely, you will hear a crackling sound like static electricity.
The same thing happens when a PVC pipe or a plastic spoon is charged with static electricity.
Why does static electricity separate salt and pepper?
When the spoon or plastic balloon is rubbed on the wool, it gains electrons, giving it an overall negative charge. This charge is what we call static electricity. When the charged balloon is placed near the salt and pepper, it polarizes the salt and pepper, leaving one end positive and the other negative. The positive end is attracted to the negatively charged balloon and pops up. Both salt and pepper are attracted to the globe, but lighter pepper jumps out more easily.
Extension activities
Think of other ways to separate salt and pepper.
Mix a mixture of salt and pepper with water. Salt dissolves in water, but pepper is insoluble and floats on the surface. Filter the water mixture to separate the pepper.
Salt is denser than pepper, so if you gently stir the mixture, the denser salt moves to the bottom.
Last updated on June 12, 2024 by Emma Vanstone
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