Which of the following occurs in all chemical changes?

• A. Energy is always absorbed.
• B. The physical state of the substance always changes.
• C. Atoms are destroyed or created.
• D. New substances with different chemical properties are formed.

Answer: (D)

Verified step by step guidance

1. Understand that a chemical change involves the transformation of substances into new substances with different chemical properties.
2. Recognize that energy changes (absorption or release) may or may not occur in every chemical change, so energy is not always absorbed.
3. Note that the physical state of a substance (solid, liquid, gas) may or may not change during a chemical reaction, so this is not a universal feature.
4. Recall the Law of Conservation of Mass, which states that atoms are neither created nor destroyed in a chemical reaction; they are simply rearranged.
5. Conclude that the defining characteristic of all chemical changes is the formation of new substances with different chemical properties.