* Physical properties can be observed or measured without changing the chemical composition of the substance. Malleability describes the ability of a substance to be hammered or rolled into thin sheets without breaking. This process doesn't change the substance's chemical makeup.

* Chemical properties describe how a substance reacts with other substances. They involve changes in chemical composition.

Example: Gold is a very malleable metal. You can hammer it into thin sheets, but the gold atoms themselves remain the same.