Iron and oxygen react together and form rust. Iron is a gray metal and oxygen is a colorless gas. Rust is a reddish-brown solid. Which of the following explains the change?
a.)The product has the same properties as the reactants because matter is conserved.
b.)The product has different chemical properties than the reactants because a chemical reaction occurred.
c.)The product only has different physical properties than the reactants because a chemical reaction occurred.