Steve Spangler explains that the reaction is caused by the small pockets of air "pits" in the Mentos candy that allows a lot of bubbles from the carbonation to form, basically releasing the gas from the soda bottle, causing a fountain.
It's really fun to try.
First you take a soda bottle and place it somewhere where a giant wet mess is going to be ok (aka the grass in a local park).
Then open the soda top (which you would save for a power vote towards Nerdy Science).
Then pop some Mentos candies into the bottle (1 will work, 2 is a little better, >2 seems a little wasteful)
Watch the explosion
Repeat (over and over and over again).
Just be careful the camera person is not in the line of action:
Things to experiment with:
1. Different sodas (warning: sugar soda leaves an icky, sticky mess).
2. Different sized bottles/cans.
3. Amount of Mentos added to soda (we started with a whole roll, but it seemed to give us a good reaction with even just 1 or 2).
4. Try different kinds of Mentos (fruit/mint).
5. Taste the soda before and after the Mentos experiment:
6. Taste the diet soda flavored Mentos.
7. Compare the Mentos you threw in the soda to fresh Mentos.
8. How high can you get the soda to shoot? Set a target to aim for. Adjust the size of the nozzle (hint: smaller diameter).
Edited 6/30/13 to remove Pepsi Refresh Voting tag. Voting has long since ended.
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