There is a lot of debate in the Science world that when Mentos react with Diet Coke, it is a chemical reaction. This statement though, is proven to be false. If you look at the definition of a chemical reaction, it is a “process that involves the rearrangement of the molecular or ionic structure of a substance.” When a Mento is dropped into Diet Coke it is’t changing the molecular structure of the substance, it is just simply changing the phyiscal structure. Instead of a chemical reaction happening, it is what they call “Nucleation.” Nucleation is the process that occurs in the forming of crystal from a solution, liquid, or vapour. All the fizz at the top of the soda is carbon dioxide, so when it is all squeezed into the soda it is looking