Which statement is true for a chemical change?

• A. A new substance with different properties is formed.
• B. The chemical composition of the substance remains unchanged.
• C. No energy is absorbed or released during the change.
• D. The process is always reversible by physical means.

Answer: (A)

Verified step by step guidance

1. Understand that a chemical change involves the transformation of substances into new substances with different chemical compositions and properties.
2. Recall that during a chemical change, the original substances' chemical bonds are broken and new bonds are formed, resulting in new substances.
3. Recognize that the statement 'A new substance with different properties is formed' aligns with the definition of a chemical change.
4. Note that the other statements are incorrect because: the chemical composition does change, energy is often absorbed or released, and chemical changes are not always reversible by physical means.
5. Conclude that the true statement for a chemical change is that a new substance with different properties is formed.