Today we are sharing one of my favorite things – a science demonstration inspired by a book. We read Benny’s Pennies and then made old, dull pennies look shine again by using common household supplies, while seeing a chemical reaction right before our eyes. Shiny penny science!
The book use to go along with this science demonstration is Benny’s Pennies by Pat Brisson. In the book, Benny starts out with 5 new pennies and decides he wants to spend them. He goes through town and spends each penny, one by one, until he has no more. After his shopping adventure, he returns home and gives the gifts to his family.
Shiny Penny Science:
We used 5 pennies for this activity (to go along with the book), but you really only need 2 for comparison. Although if your child is like mine, they may want to make all the pennies in the house shiny after they see it the first time
Here’s the pennies we started with!
What you’ll need:
- old, dull pennies
- 1/4 cup white vinegar
- 2 tsp salt
- glass or plastic cup or bowl
- plastic spoon
How to make the pennies shine!
First we added the vinegar and salt to a cup and stirred with a plastic spoon until the salt was dissolved.
Next, we added 4 of our pennies into the salt and vinegar solution. We kept one penny out to use to compare.
We could see the difference almost immediately! The became shiny pretty quickly.
We left the pennies in the solution for a few minutes and them took them out with the plastic spoon, rinsed with water, and dried them off.
We put the original penny and the one of the shiny pennies next to each other to compare. There really was quite a difference!
The science behind it:
Older pennies become dull because of they are covered in copper oxide. Copper oxide is formed when the copper from the pennies reacts with the oxygen in the air. Vinegar is an acid and reacts with the salt to remove the copper oxide.
More ways to explore:
Here’s some more ways to experiment! You can do these after doing the above, using the same solution
Make a penny turn blue-green! Add some pennies into the salt/vinegar solution following the same directions above, only this time do not rinse or wipe them off. Let them stay wet and air dry. They will slowly turn green. After coming out of the solution, the salt reacts with the air to form the compound malachite.
Here are our pennies after just a couple hours. We found that this works better when they stay on a wet paper towel during the process (we put them on a dry one to take a picture).
Make another metal copper colored: Add a bolt or washer to the same salt/vinegar solution that the pennies were in. After a little while, it will take on a copper coloring.
Here we had a shiny silver-colored washer. In the middle photo, it is added to the salt/vinegar. See the bubbles? The copper left in the vinegar became attracted to the metal washer and became copper-colored.
We are excited to be participating in Storybook Science. Be sure to follow along because every day in March bloggers will share science activities inspired by children’s books. This week is all about kitchen science – easy, doable projects that can be done with materials from around the house.
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