What is the term used when matter changes from one state to another?

When matter changes from one state to another, the term that accurately describes this phenomenon is a physical change. This occurs during processes such as melting, freezing, evaporation, condensation, and sublimation, where the substance alters its form or appearance but retains its chemical composition. For example, when ice melts into water, it undergoes a physical change; the molecules remain H2O, but the arrangement and energy of those molecules change, resulting in a different state of matter.

In contrast, a chemical change involves a transformation at the molecular level, leading to the creation of new substances. Terms like "state transition" and "phase shift" could describe similar concepts but are less commonly used in educational contexts for discussing the change of states in matter. Therefore, in the context of matter transitioning between states, physical change is the most accurate term.