Question

how do you tell wether a change is chemical or physical

Answer 1

a physical change is one in which the form of a chemical substance, but not its chemical composition. For instance, you crush a can, or you crush ice. It's still a can, and it's still "ice" but its just not the same as before.

a chemical change, on the otherhand, can be a new substance. for instance, if you mix water with pancake mix. Thats a chemical change. its no longer water or pancake mix, it's a new batter type of thing