What is the Law of Conservation of matter, and how does it apply to chemical reactions?

This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system. In other words, in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter