Which of the following best describes what happens during a physical change?

• A. Energy is always absorbed and the substance decomposes.
• B. The substance changes its physical appearance but not its chemical composition.
• C. Atoms are rearranged to form new molecules.
• D. New substances with different chemical properties are formed.

Answer: (B)

Verified step by step guidance

1. Understand the definition of a physical change: it is a change that affects the form or appearance of a substance but does not alter its chemical composition.
2. Recognize that during a physical change, the molecules or atoms of the substance remain the same; no new substances are formed.
3. Note that physical changes often involve changes in state (such as melting, freezing, or boiling) or shape, but the identity of the substance remains constant.
4. Contrast this with chemical changes, where atoms are rearranged to form new molecules and new substances with different chemical properties are produced.
5. Therefore, the best description of a physical change is that the substance changes its physical appearance but not its chemical composition.