As I have mentioned before, explosive science is always good. Screaming jelly babies, bottle tornadoes, the list is endless. Anyone who has ever been on YouTube will have seen videos showcasing the emphatic properties of mentos and diet coke.   

Basically pop a mento into a bottle of diet coke and the reaction causes a geyser effect. The science is simple; the caffeine, potassium benzoate, aspartame, and CO₂ gas contained in the Diet Coke and the gelatin and gum arabic ingredients of the Mentos all contribute to the jet effect.

In addition the physical structure of the Mentos is the most significant cause of the eruption due to nucleation. The surface of the mint Mentos is littered with many small holes, allowing CO₂ bubbles to form very rapidly and in great quantity, in turn causing the jet of foam.  

Here are some videos of the emphatic results the reaction can cause.

On a serious note: do this experiment with the greatest of care and in a controlled environment. If you want to perform more experiments, take a look at some of our science courses.