Find More  Science Experiments
What You Need:
- Liter of Diet Soda
- Roll of Mentos Candy
Definitely go outside. Set the liter of soda on a firm surface – a sidewalk will work fine. Quickly – and I mean quickly – add the roll of mentos candy. Stand back!!
Soda is fizzy because it has carbon dioxide pumped into it at the soda bottle plant. The carbon dioxide bubbles just sit there in the soda until you open the top. When you open the top some of the bubble escape making that “whisssssh” sound.
Each mentos candy has a bunch of pits on the surface. The pits are so small you can barely see them. Under a microscope the a mento would look like a golf ball. Those little pits on the surface of the mento are a perfect place for a bubble to form, this is called a nucleation site.
When you drop the candies in the soda they sink and also start making bubbles in all of those pits. The bubbles form and explode making the soda bubble up and out the top of the soda bottle.
Here are some websites and books that will give you more chemical reaction experiments to try:
- Science Buddies: Coke and Mentos – Nucleation Goes Nuclear !
- Steve Spangler Science: Mentos and Diet Coke Geyser 
- Science Buzz: Diet Coke and Mentos 
  
Words to Know:
Nucleation Site – A place where a gas can form bubbles.