In a physical change, how is the material involved characterized before and after the change?

In a physical change, the material involved retains its original composition and chemical structure, meaning that before and after the change, the characteristics of the material remain fundamentally the same. Examples of physical changes include melting ice to water, boiling water to steam, or breaking a glass. In these instances, the substances do not undergo any alteration in their molecular or chemical identity; instead, their physical state may be modified (for instance, from solid to liquid or from liquid to gas).

This perspective distinguishes physical changes from chemical changes, where a substance is transformed into a different material with a different chemical makeup. Understanding this principle is crucial in recognizing the nature of physical changes and how they differ from chemical reactions, emphasizing the consistency of the material's intrinsic properties despite alterations in physical form.