Which statement describes a chemical reaction?
a. reactants form products when atoms change state.
b. products form reactants when atoms change state.
c. reactants form products when atoms are rearranged.
d. products form reactants when atoms are rearranged.

The statement that describes a chemical reaction is the statement c. reactants form products when atoms are rearranged. The atoms of the reactants are arranged is a specific position and number forming a determined compound. In a chemical reaction, the products are different compounds than the reactants, so the atoms have to rearrange to form these new compounds (the products).