Teaching about corrosion: How to make an aluminum foil destroyer

Making an aluminum foil destroyer is an easy to do, fun and inexpensive science experiment that highlights an important scientific principle of chemistry – corrosion. This decomposition of aluminum foil is a great way to highlight what can happen when certain metals come in contact with each other. Plus, this easy science experiment is a great way for kids to view a chemical reaction firsthand rather than just reading about it.

What you’ll need for this experiment 

  • A clear drinking glass
  • Water
  • A piece of copper wire (coiled into a flat spiral shape) or an old penny (pre-1980s)
  • A piece of aluminum foil cut into a square (approximately 1-2 inches, or 2.5-5 centimeters)

Step One: Cut out a small square (approximately 1-2 inches, or 2.5-5 centimeters) from a piece of aluminum foil. Put the square piece of aluminum foil in the drinking glass, making sure that the foil is laying as flat as possible on the bottom of the glass.

Step Two: Put the piece of coiled copper wire, or the old penny, on top of the foil. Make sure that the wire or coin is in full contact with the foil. Keep in mind that pennies were made of about 95% copper until the early 1980s. So, make sure to use a penny that is minted before 1982.

Step Three: Fill the glass with water, being careful not to disturb either the copper or the aluminum foil.

Step Four: Let the glass sit undisturbed for at least one full day (24 hours). You’ll notice that the water gets a bit cloudier with every passing hour. The longer the aluminum foil and copper stay in the glass, the cloudier the water becomes.

Step Five: Carefully pour out the water, and remove the coin or piece of copper wire from the glass. Notice that the aluminum foil is perforated and has been partially eaten away around the spot where the coin or copper wire coil was laying. 

Why does this experiment work?

This is the chemistry principle of decomposition known as corrosion. Decomposition is especially common if the metal mixtures in the alloys are unevenly distributed. Since the two different metals are in contact with each other in the glass, corrosion occurs. As the aluminum foil is dissolved, the water becomes clouded. Another interesting thing about this experiment is the fact that a tiny electrical charge is produced as the decomposition process occurs. So, technically, you are creating a tiny amount of energy as you are witnessing the process of corrosion!

Teaching and learning is always more fun and rewarding with a few hands-on activities. Making an aluminum foil destroyer is one simple way for students to witness an important scientific principle in action.