We suggest students work in groups of four. Homeschool students can work on their own.

You will need access to water for this activity.

You will need old, tarnished pennies for this activity. You must use pennies dating from BEFORE 1982, when they were made from 95% copper. (Pennies made after 1982 are copper-plated zinc, which won’t work for this activity.)

We suggest asking students to bring in pennies made before 1982. You can also buy penny rolls at the bank. We bought $3 worth, sorted out the pre-1982 pennies, and had exactly 40 to work with. If you are working with a homeschool student or small group, you’ll need a minimum of 20 pennies.

Optional: Each student can use orange and brown colored pencils or crayons to show the coloration of the dull and shiny pennies on their worksheets.

In the next lesson, you’ll need to reuse some of the materials from this activity so students can copper plate a steel nail. See instructions below.

Prepare Your Testing Liquids

Cut out the Container Labels and tape one to each of your four plastic containers. You now need to prepare the four testing solutions - one for each container. If you’re working with a homeschool student or small group, you can cut the following “recipes” for each solution in half.

• Soapy Water: Mix 2 tablespoons liquid soap (or detergent) with 2 cups water.
• Vinegar: Pour 2 cups of vinegar.
• Salt & Vinegar: Mix 6 tablespoons salt with 2 cups vinegar. The salt won't all dissolve, but add it anyway.
• Salty Water: Mix 6 tablespoons salt with 2 cups water. The salt won't all dissolve, but add it anyway.

We recommend placing each container in a separate area of the classroom as a test station.

Save Materials and Prepare for the Next Lesson

• Save student work: Students will need their completed “Alchemist’s Potion, Part 1” printouts for the next lesson. Make sure they’re stored somewhere safe.

• Save the pennies in the Salt & Vinegar solution: At the end of this lesson, you’ll dump all the pennies into the Salt & Vinegar to soak overnight. (If you made just 1 cup of Salt & Vinegar, dump at least 20 pennies into it.)

• Add a nail: After students have left class, we recommend that you put a nail into the Salt & Vinegar solution with the pennies — but don’t tell your students you’re doing it. You’ll find out why in the next lesson, when your students will discover that the solution the pennies soaked in can change steel in a surprising way.