I cannot lie, I am a nerd, and I love science. Science rules. It’s not unusual for my husband and me to quote Mythbusters to each other. My kids have no hope in the matter, they are destined to grow up to be nerds too. Getting them to accept this early is the key to a long and happy life. All this is why we frequent various science experiments. This week my kids were learning about money. So to go along with that, we took a closer look at pennies.
Here is what we did. First and foremost I got a brand new penny from our bank. Then we went on the hunt for the oldest grosses looking penny we could find. These will act as our “control” for the experiment, or what we compare our results to. Once you have your control, empty those piggy banks and find the old yucky brown pennies. Get as many as you can. Get your kids to consider why the pennies are different colors. If your kids are like most, they will simply assume the pennies are dirty. While this is probably true, it’s not the only thing happening. Pennies are made of copper (actually they are copper plated. Just FYI.) When copper is exposed to oxygen, you know air, it creates carbon oxide, which creates that brown color.
Next gather a bunch of clear plastic cups. Fill one with water, one with soap and water, one with coffee, ketchup, vinegar, vinegar and a teaspoon of salt, soy sauce, mustard, soda, and anything else you can think of. Put two pennies in each cup. Wait about ten minutes. Remove your pennies, rinse one of the two from each cup with water while just wiping or patting dry the other. Then discover what happened to each penny? Which ones look cleaner? The penny in the salt and vinegar that wasn’t rinsed in water, did it turn green? (Just like the Statue of Liberty anyone?) Compare and contrast to your control pennies. Chemistry and science are fun!