Answer:
A change in state of matter
Explanation:
» Concepts
A chemical change is a change in a substance's chemical composition, causing it to go from one thing to a completely new thing. You can't go back to the original thing with a chemical change. A sound, new substance, odor production, gas release, and light production are all signs of a chemical change
With a physical change, you can easily go back to any state of matter. For example, if you melt an ice cube into water, just freeze it up again.
