What must be done to be certain that a chemical change has taken place?

Which property of physical changes explains why matter is conserved in a physical change?

If there are 8 g of a substance before a physical change, how much will there be afterwards?

When a substance changes states (melts, evaporates, etc.) it is often what type of change?

Which actions are evidence that a chemical reaction has occurred? Check all that apply.

Which of the following is a clue that a chemical change has taken place?

The oxidation of haircolor is an example of a _____.