A physical change is:

A physical change is:

• A. A change that does not alter the chemical composition.
• B. A change that produces a new substance
• C. A change that changes the molecule's identity
• D. A change that releases energy always

Answer: (A)

A physical change means the material’s chemical identity stays the same; only its form, state, or appearance changes. In a physical change, no new substance is formed, so the same molecules are present before and after. For example, ice turning into liquid water involves melting, but the substance is still H2O. The other ideas describe chemical changes: producing a new substance or changing the molecule’s identity would mean a chemical transformation. Releasing energy is not a defining feature either—some physical changes absorb energy (like melting) and others release energy, so that property isn’t universal.

A physical change means the material’s chemical identity stays the same; only its form, state, or appearance changes. In a physical change, no new substance is formed, so the same molecules are present before and after. For example, ice turning into liquid water involves melting, but the substance is still H2O. The other ideas describe chemical changes: producing a new substance or changing the molecule’s identity would mean a chemical transformation. Releasing energy is not a defining feature either—some physical changes absorb energy (like melting) and others release energy, so that property isn’t universal.