* Physical Changes: Alter the form or appearance of a substance, but not its chemical composition.

* Examples: Melting, freezing, boiling, condensation, cutting, crushing.

* Chemical Changes: Result in the formation of new substances with different chemical properties.

* Examples: Burning, rusting, cooking, digestion.

When water freezes into ice, it changes state from liquid to solid. The molecules of water (H₂O) remain the same; they just arrange themselves differently in a more rigid, crystalline structure.

Let me know if you have any more questions!