All matter, which makes up all things, can be changed in two ways: chemically and physically. Both chemical and physical changes affect the state of matter. Physical changes are those that do not change the actual substance. For example, clay will flatten if squeezed, but it will still be clay. Changing the shape of clay is a physical change and does not change the matter’s identity. Chemical changes turn the matter into something new. For example, when the paper is burned, it becomes ash and will never be paper again. The difference is that physical changes are temporary or only last a little while. Chemical changes are permanent, which means they last forever. Physical and chemical changes both affect the state of matter.

Which sentence below best explains the concept of chemical change?