* Physical Changes: Alter the form or appearance of a substance but don't change its chemical composition.

* Example: Water (H₂O) changes from liquid to gas (steam) when boiled, but it's still water.

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

* Example: Burning wood creates ash, carbon dioxide, and other substances, completely changing the original wood.

In the case of boiling water for soup:

* You're simply changing the state of water from liquid to gas (steam).

* The chemical composition (H₂O) remains the same.

* You can condense the steam back into water, demonstrating that the change is reversible.

Let me know if you have any other questions!