Chemical reactions are always surprising for kids to observe! In this science activity we’ll be turning a penny green (similar to what happens to The Statue of Liberty!)
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Chemical reactions are such a great way to pique a child’s curiosity. This experiment involving a chemical reaction is quite simple and always amazes kids! (This post contains affiliate links.)
Materials for Turning a Penny Green
- Copper pennies
- White vinegar
- Dish or bowl
- Paper towel
- free observation printable (optional)
Procedure for Penny Chemical Reaction
1. Fold a paper towel so that it fits inside your dish.
2. Place the pennies on top of the paper towel.
The pennies placed on the paper towel
3. Pour vinegar over the pennies so that the paper towel is fully saturated.
Pennies with vinegar ready to be observed
4. Observe the pennies over the next few hours and days. You can record your observations using the free printable.
Tips
We left this experiment out for a few days, adding more vinegar as the paper towel began to dry out and flipping the pennies over occasionally. The longer we waited, the more green they became!
Question to Spark Curiosity & Critical Thinking
What happened to the pennies over time? What is your theory as to why this happened?
Can you think of any other chemical reactions you’ve seen in everyday life?
What’s Going On
A chemical reaction has occurred! (A chemical reaction is the combination of two reactants to form something entirely new.) A penny is made of copper. The vinegar on the paper towel helps the copper in the penny easily react with the oxygen in the air to form a blue-green colored compound called malachite.
This is similar to why the Statue of Liberty (which is covered with a layer of copper) has turned greenish-blue. The statue would naturally turn greenish-blue due to exposure to the oxygen in the air. However, because some rain has acid from pollution in it, the rain speeds up the reaction (just as the vinegar caused the reaction with the penny).
Want to go even further?
Even more activities to inspire creativity and critical thinking for various ages.
- Try a similar experiment: Fill a cup with 1/4 cup vinegar and 1 teaspoon salt. Stir. Add some pennies and let them sit for 5 minutes. Take them out and rinse them. What happened?
- Make a volcano using baking soda and vinegar.
- Make a torch and crown just like the Statue of Liberty!
What a great science activity! We’ll have to do this one this week. Thanks!
Seriously? I cannot believe I didn’t know you could do this with vinegar! I have a copper tea pot and a milk can that I have let nature take care of, and it’s taking YEARS for them to turn green! Guess what I’ll be giving them a shot of?!
I know! So much fun! Ooh, I bet that copper tea pot is just gorgeous~ I’m filled with envy thinking about it! 🙂
What a great experiment!! We will have to try it after our post using the Statue of Liberty as our symbol of NYC. Thank you for sharing at Sharing Saturday!!
Oh, I am curious to try it out. I would expect the vinegar to actually clean the coins, but I can see that letting them dry out in vinegar would accelerate oxidation.
To clean the coins you use salt!
to clean coins you use salt soap and water
I did the experiment for a class project to see what would make a penny turn green: salt water or freash water turns out neither! They clean the penny of!!!
I’ve seen a lot of experiments for turning them back to copper colored, this is the first one I’ve seen to turn them green.
Thanks for linking up to Science Sunday!
What a great science activity! I think this would be a great, meaningful activity when talking about the Statue of Liberty (as you mentioned). Thanks for sharing at Stress-Free Sunday — I’m featuring you this weekend!
Great activity!! I’m featuring this tomorrow at the After School Linky Party. Stop by to check it out and share more of your great ideas while you’re there! Thanks!
Love the activity. Featuring you on iGameMom. Thanks for sharing at Mom’s library. http://igamemom.com/2013/09/25/creative-science-activities-for-kids-moms-library/
HI,
I can’t wait to try this with my kindergartners, however I can’t seem to access the printable. When I click on it I’m taken to a google doc page that is denying access. Help!
Thanks!
Whitney
Sent you an email, Whitney! 🙂
What is the reaction that is taking place to tarnish the pennies?
Hi Trish- What’s happening is the copper in the penny is reacting with the oxygen in the air to form the green-colored copper oxide. Although pennies are mainly zinc now, they are still plated in copper. Hope that helps!
Is the blue greenish toxic or dangerous to our health in anyway?
I did it experiment magic pencil the children love it. thanks Pilar
Love this experiment. We are going to the Statue of Liberty this summer and this will tie in perfectly. I cannot access the penny printable observation sheet. Would it be possible for you to email it to me, please? Thank you in advance!
Kind Regards,
Natasha