Which statement describes a chemical reaction involving rearrangement of atoms?

• A. It breaks and forms bonds to rearrange atoms
• B. It dissolves substances in water
• C. It changes the nucleus of atoms
• D. It requires no energy change

Answer: (A)

Chemical reactions involve breaking existing bonds and forming new bonds, which allows atoms to be rearranged into different substances. This rearrangement is what leads to products with different properties from the reactants. The statement describing this process is the one that says bonds are broken and formed to rearrange atoms. Dissolving substances in water is mainly a physical process of dispersion, not a chemical rearrangement of bonds. Changing the nucleus would be a nuclear event, not a chemical one. And many chemical reactions do involve energy changes, so saying there is no energy change isn’t accurate for the general concept.