Which of the following best describes the difference between a chemical change and a physical change?

• A. A chemical change can be easily reversed, but a physical change cannot.
• B. A physical change always involves a change in temperature, while a chemical change does not.
• C. A physical change produces energy, whereas a chemical change does not.
• D. A chemical change results in the formation of new substances with different chemical properties, while a physical change does not alter the chemical composition of a substance.

Answer: (D)

Verified step by step guidance

1. Understand the definitions: A physical change affects the form or appearance of a substance but does not change its chemical composition, while a chemical change results in the formation of one or more new substances with different chemical properties.
2. Recognize that physical changes include changes in state (like melting, freezing, or boiling) or shape, and these changes are usually reversible without altering the substance's identity.
3. Identify that chemical changes involve breaking and forming chemical bonds, leading to new substances; examples include rusting, burning, or digestion.
4. Note that reversibility is not a definitive criterion since some physical changes can be irreversible and some chemical changes can be reversed under certain conditions.
5. Conclude that the key difference lies in whether the chemical composition changes: chemical changes produce new substances, whereas physical changes do not.