is it physical or chemical reaction when u r doing it as a project (dietcoke and mento's)?

Question

science prodject

Answer 1

chemical

Answer 2

It is Physical, Ask the Mythbusters

There has been a lot of discussion online about why Diet Coke and Mentos make such an interesting combination. What everyone can agree on is that the carbon dioxide that has been compressed into the soda escapes so rapidly that the pressure pushes the soda out of the bottle. It’s like shaking a bottle before you open it, but even more dramatic.
Gum Arabic? Not So Fast.
Several people theorized that a substance called gum arabic in the Mentos breaks the surface tension of the soda, allowing the carbon dioxide bubbles to escape rapidly. This explanation doesn’t completely work. One thing that casts doubt on the gum arabic theory is that several items (like pennies!) that contain no gum arabic whatsoever also cause soda to foam violently. Several chemists have since stepped forward to say that while gum arabic may contribute to the reaction, that can’t be the only cause.
These chemists are saying that the primary cause is physical, not chemical. Their explanation: nucleation sites. If you have a liquid that is supersaturated with gas (like soda, which is pumped full of carbon dioxide), a nucleation site is a place where the gas is able to form bubbles. Nucleation sites can be scratches on a surface or specks of dust – anywhere that you have a high surface area in a very small volume. That's where bubbles can form.

Mentos seem to be loaded with nucleation sites. In other words, there are so many microscopic nooks and crannies on the surface of a Mento that an incredible number of bubbles will form when you drop it in a bottle of soda. Since the Mentos are also heavy enough to sink, they react with the soda all the way to the bottom. The escaping bubbles quickly turn into a raging foam, and the pressure builds dramatically. Before you know it, you've got a big geyser happening!

Answer 3

Chemical

Answer 4

I thought it was physical, although it would seem to be chemical. I'm not sure why. I'm not even sure if the scientists know for sure which one it is. Read the article I'm posting the link to.

Answer 5

chemical b/c you cant but it back into its origional state