Answer the following question given this paragraph: 

One of the fundamental laws of chemistry deals with the fact that we cannot (using chemical means) create or destroy matter. When a reaction is run, the number of atoms of each specific type must be the same on both sides of the equation. For some materials, it turns out that one element can combine with a second element in more than one ratio. Carrying out mass ratio calculations helped establish the law of multiple proportions.


Q: One of the fundamental laws of chemistry deals with the fact that we cannot create or destroy what?


A:
matter