Which of the following best describes what occurs during a chemical reaction?

• A. Only the physical state of the substances changes, but their chemical identities remain the same.
• B. Atoms are rearranged to form new substances with different chemical properties.
• C. Electrons are never involved in the process.
• D. Atoms are destroyed and disappear from the system.

Answer: (B)

Verified step by step guidance

1. Understand that a chemical reaction involves changes at the atomic or molecular level, not just physical changes like state or shape.
2. Recall that during a chemical reaction, atoms are neither created nor destroyed; instead, they are rearranged to form new substances.
3. Recognize that electrons play a crucial role in chemical reactions because bonds between atoms are formed or broken by the movement or sharing of electrons.
4. Eliminate options that suggest only physical changes occur or that atoms are destroyed, as these contradict the law of conservation of mass.
5. Conclude that the best description of a chemical reaction is that atoms are rearranged to form new substances with different chemical properties.