What term is used for the alteration of properties of matter without forming a new substance?

The term that describes the alteration of properties of matter without forming a new substance is known as a physical change. In a physical change, the material may change its form, state, or appearance, but the fundamental composition remains the same. Examples of physical changes include melting ice into water, boiling water to form steam, or dissolving sugar in tea.

During these processes, the matter does not undergo a chemical reaction that alters its molecular structure; instead, it simply changes its state or form. This is in contrast to a chemical change, where new substances are formed due to the breaking and forming of chemical bonds. Physical changes are often reversible, while chemical changes usually result in irreversible transformations. Understanding this distinction is crucial in various scientific fields, including chemistry and materials science.