We’re late the to the game on this one, but better late than never! Apparently big kids and science teachers have been exploding diet soda with Mentos for years now, but this activity was definitely new to my 4-year-old, and the perfect summer science experiment. Get outside – some place with lots of room – and then watch the geysers explode!

For the most fun, purchase several large bottles of diet soda in different varieties, so you can compare the height of the geysers (big kids may want to be more scientific about this, measuring off the heights, but we simply had fun).

Line up the bottles, and drop five Mentos (very quickly!) into them one at a time. Note: You can drop in as many as seven Mentos, but by five, I had to run in the other direction.

 

Now here’s the important step – move back! The geyser is going to happen fast, and high.

The diet root beer took me so completely by surprise that I only had time for a picture of the aftermath.

By the diet Coke, I was ready with my camera.

Interestingly, diet Mountain Dew only gave us a small fizz.

Travis loved hosing off the driveway in the aftermath!

Which sodas did you try? Please share in the comments!