Which term refers to a change of state without chemical change?

Which term refers to a change of state without chemical change?

• A. A chemical reaction
• B. Oxidation
• C. Phase change
• D. Hydrolysis

Answer: (C)

Phase change is a change of state without changing the chemical identity of the substance. When a solid becomes a liquid or a liquid becomes a gas (or the reverse), energy is used to rearrange how the molecules are arranged and move, but the molecules themselves stay the same. There’s no new substance formed, just a different form of the same material—for example, ice melting into liquid water or water boiling into steam. Other terms describe chemical changes, where bonds are broken and new substances are produced, such as oxidation (electron transfer) or hydrolysis (reaction with water breaking bonds).

Phase change is a change of state without changing the chemical identity of the substance. When a solid becomes a liquid or a liquid becomes a gas (or the reverse), energy is used to rearrange how the molecules are arranged and move, but the molecules themselves stay the same. There’s no new substance formed, just a different form of the same material—for example, ice melting into liquid water or water boiling into steam. Other terms describe chemical changes, where bonds are broken and new substances are produced, such as oxidation (electron transfer) or hydrolysis (reaction with water breaking bonds).