ISupposeWe Clean Pennies

This experiment is to clean old, dirty pennies using resources near you.

Materials needed: old pennies, 1/4 cup of white vinegar, 1 tsp salt, nonmetal bowl, and paper towels

Procedure:

1. Pour the vinegar into the bowl and add salt

2. Put about five pennies into the bowl and count to ten slowly
3. Take the pennies out and wipe them with the paper towel

4. You will have shiny pennies!

Safety Precautions:

• Don't use collectible coins, you will lower their value
• Wear safety goggles so you don't get any vinegar in your eyes
• Do not mix pennies with any other coins or they will become discolored
• Do not use scratched pennies or pennies older than 1982, they may become hollowed out due to the fact that vinegar dissolves zinc

Scientific Principles:

1. Vinegar acid reacts with salt to remove copper oxide

2. If you don't dry the pennies, the acid will create malachite on them.

If you are interested in different ways to clean your pennies, there are several solutions:

• Vinegar and baking soda
• Vinegar and lemon juice
• Video example