Penny Experiment

Contributor: Samantha Penna. Lesson ID: 11920

No one likes having a dirty face, not even Abraham Lincoln! We're talking about dirty pennies, of course! A penny doesn't buy much, but it makes a good science experiment! Figure out how to clean one!


Scientific Method

learning style
personality style
Grade Level
Primary (K-2)
Lesson Type
Quick Query

Lesson Plan - Get It!

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  • Why do pennies get dirty?

An even better question:

  • How do you clean them?
  • Car wash?
  • Shower?
  • Dishwasher?
  • Toothpaste?

Pennies are made of copper.

The copper on a penny reacts with the oxygen in the air. This causes it to get dull, dirty, and even turn green! Have you ever seen a dirty penny before? What did it look like? Tell your parent or teacher.


You will conduct an experiment with dirty pennies. You will use different ingredients to try to clean a penny. Before you begin the experiment, you will need to come up with a question. All scientists come up with a question before beginning an experiment. With the help of your parent or teacher, come up with a question about the best ingredient for cleaning pennies.


Your goal is to find out which ingredient will make a penny the cleanest. Below you can read a list of the ingredients you will use to clean a penny:

  • vinegar
  • water
  • dish soap
  • lemon juice
  • salt
  • hot sauce

Once you have all of your supplies ready, read the experiment description below:

You will submerge dirty pennies in different ingredients. You will find out which ingredient cleans pennies the best.

The goal of the experiment is to figure out which ingredient(s) will be most effective in cleaning a dirty penny. You will create a hypothesis (guess or prediction) about what the result of the experiment will be. Your hypothesis will state which ingredient(s) you think will clean the penny the best. Read the example hypothesis below:

"If I place a penny in a cup of lemon juice, then the penny will become shiny and clean."

With the help of your parent or teacher, make a hypothesis (prediction). Once you have created your hypothesis, move on to the Got It? section to start the experiment.

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