Which statement describes a physical change?

Which statement describes a physical change?

• A. Change in chemical composition
• B. Change in state without chemical composition change
• C. Formation of a new substance
• D. Release of energy

Answer: (B)

Physical changes involve altering a substance’s form or state without changing its chemical identity. When a substance changes state—like ice melting, water boiling, or a solid turning into a gas—the molecules remain the same substance; no new chemical species are produced, and the process can often be reversed. This is exactly what the statement describes: a change in state without a change in chemical composition. In contrast, changes that involve a different arrangement of atoms to form new substances—chemical changes—result in a different substance with new properties. Energy release can occur in both physical and chemical processes, so it doesn’t by itself define a physical change. Examples like melting or boiling illustrate a physical change because they involve state changes without forming new substances.

Physical changes involve altering a substance’s form or state without changing its chemical identity. When a substance changes state—like ice melting, water boiling, or a solid turning into a gas—the molecules remain the same substance; no new chemical species are produced, and the process can often be reversed. This is exactly what the statement describes: a change in state without a change in chemical composition. In contrast, changes that involve a different arrangement of atoms to form new substances—chemical changes—result in a different substance with new properties. Energy release can occur in both physical and chemical processes, so it doesn’t by itself define a physical change. Examples like melting or boiling illustrate a physical change because they involve state changes without forming new substances.