Explanation:  Mentos + Diet Coke = Nucleation
According to a 2006 episode of Mythbusters, it is believed that the caffeine, potassium benzoate, aspartame (artificial sweetener) and the CO2 gas in the soda (Diet Coke works best) combine with the gelatin and gum Arabic of the Mentos to create the explosive effect.  Mint Mentos work best because [...]