Six Ways to Clean a Penny: A Simple Science Experiment

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Playful Learning: Six Ways to Clean a Penny

Most of us probably remember the classic science experiment of cleaning a penny with a mixture of vinegar and salt. There is always something so magical and exciting about tossing in a dirty penny and seeing a beautiful clean and shiny penny come out. Well, my seven year old and I decided to take the experiment one step further. What else could we use to clean a penny?

We assembled various solutions from what we had around the house. Lemon juice, cola, ketchup, tabasco sauce and just plain old water. I had read about trying tabasco sauce and ketchup somewhere once so we were anxious to see what it would do to the pennies, if anything.

Playful Leanring: Six Ways to Clean a Penny

We tossed in our six tarnished pennies and waited for about ten minutes before we allowed ourselves to check on them. While we waited, we hypothesized. Which solutions might work? Which ones might not work? Which solution did we think would work the best?

After ten minutes we dried our pennies with a paper towel and examined the results. We asked questions like…Which solution produced the shiniest penny? Were you surprised any of the solutions worked? After a little studying we decide to see what would happen if we let the pennies soak a little longer. We popped them back in to their corresponding bowls and left them to soak for another twenty minutes.

Playful Learning: Six Ways to Clean a Penny

In total after an half an hour we had a fair share of shiny pennies. Some solutions worked better than others. The water didn’t really work at all, and we pretty much knew that it wouldn’t going in, but we wanted a baseline to compare our results to. We cleaned off our pennies one last time and studied them again making observations and asking questions as we went along. Some of our observations were very interesting. For example, the penny that was cleaned in tabasco sauce had gotten cleaner but it had a slight tinge of color to it. The ketchup penny was fairly shiny and that surprised us. The penny in the lemon juice seemed to be the shiniest. I think you get the idea πŸ™‚ Try it! Have some fun cleaning pennies. Try different solutions, hypothesize, and then talk about your results as you observe them. It was certainly lots of fun for us. Ask your child some of the questions we used or just ask them to tell you about their observations and see what they come up with on their own. You may be surprised.

Playful Learning: Six Ways to Clean a Penny

Another fun piece of this project was to line the pennies up after the fact and see if we could guess which penny was cleaned in which solution by remembering what we observed. Can you tell which penny was cleaned with just water? Can you tell which one was cleaned in the tabasco sauce? Hint: use all your senses…we could tell which penny was cleaned in the ketchup from the smell. What other solutions can you think of to use to try and clean pennies?



Jen started blogging as a creative outlet after deciding to stay at home with the birth of her youngest. She is a Mom to two boys and stepmom to two. She blogs about all of their goings on over at Plain Vanilla Mom. The blog focuses a lot on the activities she does with the babe, but there’s plenty there for the older kids too. Jen’s personal hobbies fall into two categories…baking & photography and you will find a bit of both on the blog as well.



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  1. This is a great idea. I never thought about trying things like tabasco sauce ane ketchup. I like that you hypothezied and asked lot of questions.

  2. My children actually just cleaned a bunch of pennies with ketchup. Thanks for showing us how to take it even further in to a fun science experiment!

  3. I work with stuff like this out here in Zaamslag, Netherlands.
    Actually doing what you enjoy and writing about it in such a great way is
    a great gift. Your informative article possesses the perfect combo of
    enthusiasm and well-written, interesting content that I’ve grown to love and admire.

  4. wow i did a survey inspired from this article and i asked witch liquid would work the best to clean a penny and 10 out of 24 people picked cola and no one picked ketchup and boy, will they be surprised about how this project worked along ! I am using this project as my project that counts on my science grade. I am so exited to start , thank you so much!

  5. Love this! Thank you for sharing!! I will ise thos tmrw with my SPED students.

    I will refer back to this blog for other great things. Keep doong what your doing. I can tell you are a very dedicated teacher and collaborator.

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