Which statement best describes how particles differ after a chemical change compared to before the change?

• A. The particles are rearranged to form new substances with different chemical properties.
• B. The particles become smaller, but their composition does not change.
• C. The particles are only physically separated, not chemically altered.
• D. The particles move faster, but their chemical identity remains the same.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what a chemical change means. A chemical change involves the breaking and forming of chemical bonds, resulting in new substances with different chemical properties.
2. Step 2: Recognize that during a chemical change, the original particles (atoms or molecules) are rearranged to form new particles. This rearrangement changes the chemical identity of the substances involved.
3. Step 3: Contrast this with physical changes, where particles may move or separate but their chemical composition remains unchanged.
4. Step 4: Note that particles do not become smaller during a chemical change; atoms themselves are not broken down into smaller particles in typical chemical reactions.
5. Step 5: Conclude that the best description of particles after a chemical change is that they are rearranged to form new substances with different chemical properties.