A physical change of matter is a change that alters the form or appearance of a substance but doesn't change its chemical composition. In simpler terms, it's a change that you can usually reverse.

Here's a breakdown:

* No new substances are formed. The molecules of the substance remain the same.

* Changes are usually reversible. You can often get the original substance back.

* Often involves changes in state of matter: Solid to liquid, liquid to gas, etc.

Examples of physical changes:

* Melting ice: Solid water (ice) changes to liquid water (water), but it's still H2O.

* Boiling water: Liquid water (water) changes to gaseous water (steam), but it's still H2O.

* Cutting paper: You change the shape of the paper, but it's still paper.

* Crushing a can: You change the shape of the can, but it's still aluminum.

* Dissolving sugar in water: The sugar disappears, but it's still sugar molecules in the water.

Key points to remember:

* Temperature change can often trigger physical changes (e.g., melting, freezing, boiling).

* Physical changes are usually easily observed. You can see or feel the change.

Let me know if you'd like more examples or want to explore the difference between physical and chemical changes in more detail!