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

* Examples: Melting ice, cutting paper, bending a wire.

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

* Examples: Burning wood, rusting iron, cooking an egg.

When you pound a sheet of copper into a bowl, you are simply changing its shape and form. The copper atoms themselves remain the same. It's a physical change.