Which statement best describes a physical change?

• A. The substance changes its physical form but not its chemical identity.
• B. Atoms are rearranged to form new molecules.
• C. Energy is always released in the form of heat or light.
• D. New substances with different chemical properties are formed.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a physical change: it involves a change in the physical properties of a substance, such as its shape, phase, or appearance, without altering its chemical composition or identity.
2. Recognize that in a physical change, the molecules or atoms remain the same; they are not rearranged to form new substances.
3. Contrast this with a chemical change, where atoms are rearranged to form new molecules, resulting in new substances with different chemical properties.
4. Note that energy changes (like heat or light) can occur in both physical and chemical changes, so energy release alone does not define the type of change.
5. Conclude that the best description of a physical change is when the substance changes its physical form but not its chemical identity.