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How to Clean Pennies Chemistry Experiment

Do you know how to clean pennies? What liquids can clean a penny? Use household liquids to explore oxidation with this penny cleaning chemistry experiment for kids and figure out the best way to clean a penny!

What’s better than a shiny, new penny? Not much for a 5-year old! My Kindergartner thinks that pennies are amazing and I love her for it!

Unfortunately, we have a bunch of dull, old pennies hanging around that aren’t very pretty. We wanted to determine if there were liquids we had around the house that would remove the copper oxide on our pennies and reveal shiny, pretty pennies underneath!

BH Pretty Penny Chemistry Experiment

We set out to explore more about oxidation and why our pennies were so dull and learn how to clean pennies!

I did this activity with my Kindergartner and my 5th grader and adapted it to their different learning levels. For younger learners, you can focus more on the difference between old and new pennies and identify the physical properties of each penny before and after the experiment.

For older learners, you can incorporate questions about acids and bases and discuss the pH scale and observe a chemical reaction. They should be able to explain how to clean pennies after completing the activity.

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Why STEAM Activities?

STEAM is the abbreviation for Science, Technology, Engineering, Art, and Math.

For the month of October, we will be sharing a daily low-prep STEAM (Science, Technology, Engineering, Art, Math) activity. You and your kiddos are going to love all of the low-prep STEAM activities that we have in store at OurFamilyCode! #daysofSTEAM #31dayschallenge #STEAMactivitiesforkids #monthofSTEAM #scienceforkids #engineeringforkids #technologyforkids #artforkids #mathforkids #lowprepSTEAM #5minuteSTEAM #STEAM #STEM

STEAM, like STEM, is an integrated approach to learning that encourages learners to make connections between the concepts they are learning and how they apply them to real-world problems.

STEAM helps students ask questions, problem solve, think creatively, and produce innovative solutions. Many schools have adopted STEAM learning activities into their curriculum, but it’s never too early to start building critical thinking skills.

We love to learn through play at our house and have a blast doing activities for toddlers all the way to tweens!

STEAM Kids Pin

Looking for some more hands-on activities that incorporate Science, Technology, Engineering, Art, and Math (STEAM)? Then you have to check out STEAM Kids! 

This book features more than 50 hands-on activities that are organized into easy to implement categories, so you know exactly what concepts your kids are learning! 

Grab your copy from Amazon today or get instant access to this great book by purchasing a downloadable PDF!

You might also enjoy: Ogre Slime: Oozing Slime Sensory Fun!

Key Penny Cleaning Chemistry Terms

Physical Properties are properties of a substance that can be observed through our senses like smelling, touching, or seeing. A chemical property is a property of a substance that is revealed by the way it interacts with other substances.

Physical Change is a change that alters the appearance of a substance that can be observed by our senses. A chemical reaction is a change in the molecular structure of a substance.

Oxidation is a chemical reaction that occurs when oxygen interacts with other substances. In pennies, copper and oxygen react to form copper oxides, which leaves a dull coating on pennies. This is also the chemical reaction that gave us the green color of the Statue of Liberty.

An acid is a solution that has a higher amount of hydrogen ions than water. Vinegar is an acid. A base is a solution that has a lower amount of hydrogen ions than water. Baking soda is an example of a base. When a solution is neutral, it has a concentration of hydrogen ions equal to water.

Penny Cleaning Chemistry Experiment Supplies

  • 1 Shiny, Pretty Penny
  • 6 Old Pennies
  • Vinegar
  • Soda
  • Ketchup
  • Lemon juice
  • Water
  • Paper towels
  • Spoon
  • Timer

How to Clean Pennies Chemistry Experiment

Compare an older penny with a newer penny. Discuss the physical properties of each (for example, the newer penny is shiny). Write down your observations.

New Penny and Older Penny

Label your cups to match the liquids that you will be using. We used water, lemon juice, soda (Pepsi), ketchup, and vinegar.

Next, hypothesize what substance might be the most effective and why?

Pretty Penny Chemistry Experiment

Place a penny in each of your liquids. Set your control penny aside. You’ll use this to compare physical change. Make sure that your pennies are covered.

Set a timer for 10 minutes. During that time, discuss oxidation and chemical reactions. Name some chemical reactions that happen every day.

After 10 minutes has passed, remove your pennies one by one. Wipe each penny well with a paper towel.

Discuss the physical change for each of the pennies? What substance worked best? Is your hypothesis valid? Why or why not?  

Final Result from Penny STEAM Experiment
STEAM word design

Connect this Penny Chemistry Experiment with other STEAM Buckets

Check out this STEAM extensions!


This activity is primarily science related. In this chemistry STEAM activity, we discussed chemical reactions, made a hypothesis, conducted experiment, and recorded observations.


Take before and after pictures of your pennies for each liquid. Use the pictures to compare physical changes for each penny. Make a short presentation about your pennies and the physical changes you observed.


Try a different way of doing this experiment like using eye droppers to put the liquid on one side of the penny and letting it sit there. What method works best? 


Draw pictures to show the oxidation of your pennies and the physical change after your experiment.


Use a measuring cup to measure out each liquid. Do the experiment again and use different amounts for each.

Looking for more chemistry activities? Check these out!

31 Days of STEAM Activities AD

31 Days of Low-Prep STEAM Activities for Kids

This activity is part of our 31 Days of Low-Prep STEAM Activities for Kids. Every activity focuses on each of the buckets of STEAM (Science, Technology, Engineering, Art, & Math) although these integrated projects fit in more than one bucket.

You and your kiddos are going to love all of the activities that we have in store! Visit the 31 Days of Low-Prep STEAM Activity hub and pin it, so you can come back and visit it daily!


a picture of how to clean pennies blog image with beakers on white background

Food Science Activities

Find more activities that use food to explore Science, Technology, Engineering, Art, and Math!

Meet Toni, the Maker Mom behind Our Family Code

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Hey there, I’m Toni! I’m a software engineer and Maker Mom that finds my joy in unleashing my children’s curiosity by exploring STEAM concepts with my fantastic five!

When I’m not chasing toddlers or raising tweens, you can find me tearing things up and putting them back together over here at Our Family Code.

I am the owner and content creator of multiple educational websites designed to increase access to STEAM & STEM education with a focus on teaching computer science and coding to kids of all ages!

You can also find out more about me by visiting!

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Saturday 6th of October 2018

This penny activity is sich a classic and I love how you described the different terms and suggested ways to bring all the components of STEAM into it

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