What type of change, physical or chemical, takes place in each of the following?c. A tree is cut into boards at a saw mill.

A physical change involves a transformation that does not alter the chemical composition of a substance. Examples include changes in state, shape, or size, such as melting, freezing, or cutting. In the context of the question, cutting a tree into boards is a physical change because the wood's chemical structure remains unchanged.

A chemical change results in the formation of one or more new substances with different chemical properties. This type of change involves breaking and forming chemical bonds, as seen in processes like combustion or rusting. Unlike physical changes, chemical changes are often irreversible under normal conditions.

Understanding the distinction between physical and chemical changes is crucial in chemistry. Physical changes can often be reversed, while chemical changes typically cannot. This distinction helps in identifying processes in everyday life and in laboratory settings, allowing for better predictions of material behavior.