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

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

When you grind a sugar cube:

* You're only changing its size and shape.

* The chemical makeup of the sugar (sucrose) remains the same.

* You can still dissolve the ground sugar in water and get the same sweet taste.

A chemical change involving sugar would be:

* Burning the sugar: This would create ash, carbon dioxide, and water, changing the sugar's chemical composition.

Let me know if you'd like to explore more examples of physical and chemical changes!