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How to Make Pennies Turn Green

Uncover the mystery of the Statue of Liberty with this fun science experiment for kids. With pennies and other simple ingredients from your kitchen, you’ll be creating chemical reactions that will have the whole family talking.


Paper towels

Dish or bowl

Copper-colored pennies

White vinegar


  1. First, take your paper towel and fold it so it will fit into the bowl or dish you’ve selected for the experiment.
  2. Place the paper towel inside the dish and arrange your pennies on top.
  3. Pour the vinegar over the pennies until the entire towel is wet. It’s important for the paper towel to be fully saturated.
  4. Time to observe! Watch the pennies over the next few hours and days to gradually see the chemical reaction occur. Take notes on the changes you see in the coloring of the pennies.

Tip: When the paper towel begins to dry out, make sure you pour some additional vinegar on top. This will prolong the experiment and allow for a bigger reaction to happen. You can also flip the pennies over to see how the reaction has occurred on both sides.

Congratulations, you just created a chemical reaction using materials from your own kitchen! But why did the pennies turn green? Let’s think about the different types of material you worked with and their properties.

  1. The pennies were made of copper
  2. The vinegar contained acid

When the vinegar and the copper meet, their chemical components interact with the oxygen in the air to create a blue material called malachite.

We’ve all see the greenish blue Statue of Liberty, but did you know Lady Liberty was once a copper color? That’s right, the famous statue was once covered in a thin layer of copper and was bronze when she first arrived in the United States from France. Acid in rain covers the Statue of Liberty whenever storms hit New York, and her exposure to oxygen from being in the middle of the ocean gradually turned her blue over the years.

That’s one big chemical reaction!