Mentos/Diet Coke geyser

You'll find the Mentos/Diet Coke geyser in Candy Experiments, because no candy experiments book would be complete without it. I tested different kinds of soda and different kinds of Mentos delivery systems, watched Mentos/Diet Coke videos and TV shows like Mythbusters, and read scientific papers about the various reasons that the soda creates such tall fountains, and asked my parents to photograph it for me. Some things I learned:

• Experts say that diet cola makes the highest geyser
  
• The Steve Spangler Geyser Tube makes a higher geyser than if you just drop Mentos in the bottle. Also, it's nice to be able to start the geyser from a safe distance away, so you don't get sticky.
  
• While Mentos make the very best geyser, bumpy Nerds jelly beans are a good runner up, because of the extra surface area.

You'll find more information in Candy Experiments.

This experiment has been around for years, and there are lots of fun versions of it on the internet.

• In 2005, Steve Spangler turned this experiment from a science classroom standard into an internet phenomenon with his original Mentos/Diet Coke video.
• Eepybird has done amazing feats with Mentos/Diet Coke such as this fountain or this appearance before Blue Man Group.
• Mythbusters explores the Mentos/Diet Coke science