Question

in a chemical change, gases, heat, or light are often released and the change usually cant be undone (they are irreversible). a change in chemical properties and composition occurs and a new substance is formed. examples of this include burning, cooking, rusting, and rotting.
in a physical change, a substance changes in size, shape, or state, or two substances are mixed together. the physical properties of the substance change but not their chemical composition. no new substances are formed. they are usually reversible. physical changes include boiling, melting, and freezing.
compare physical and chemical changes by completing the graphic organizer.
check your understanding
learning goal 1
i can recall the definitions of physical and chemical change
i can summarize the main difference between physical and chemical changes
learning goal 2
i can identify examples of physical and chemical change

Explanation:

Physical change involves a change in size, shape, state or mixing of substances without altering chemical composition, and is usually reversible. Chemical change involves release of gases, heat or light, change in chemical properties and composition, formation of a new substance, and is usually irreversible.

Answer:

Physical change - Definition: A substance changes in size, shape, or state, or two substances are mixed together without changing their chemical composition. Usually reversible.
Examples: Boiling, melting, freezing.
Chemical change - Definition: Gases, heat, or light are often released, there is a change in chemical properties and composition, and a new substance is formed. Usually irreversible.
Examples: Burning, cooking, rusting, rotting.