Eighth-grade scientists have been practicing using the scientific method to design controlled experiments. Each group worked to isolate a single independent variable to help narrow down what it is about Mentos and Diet Coke that causes an eruption when they mix. They got explosive results! Watch a video see the experiment in action, and see more photos of the experiment in our photo gallery.
Want to try this experiment at home? Here are instructions for erupting Diet Coke with Mentos (adapted from Scientific American)
What You’ll Need:
- A two-liter bottle of Diet Coke
- 2 rolls of Mentos Mints
- An index card or a large plastic test tube
- A yardstick (optional)
- Outdoor space, with a clearing (and one that can get messy!)
- Safety goggles
- A partner
Step 1: Remove the lid from the Diet Coke bottle and set the bottle on a flat surface
Step 2: Roll the index card into a tube that can hold the Mentos loosely and tape the tube together (or use the test tube) Fill up the paper or the test tube with Mentos (between 4-7).
Step 3: Put your safety goggles on!
Step 4: Have one person hold the bottle. If you want to measure the explosion, hold the yardstick with the bottle of soda or tape the yardstick to the bottle if this is easier. Then, have another person use the index card or plastic tube to quickly drop the Mentos mints into the soda.