Which statement best reflects the Law of Conservation of Mass in a chemical reaction?

• A. Matter Is Destroyed.
• B. New Substances Are Formed.
• C. The Total Amount of Matter Stays the Same.
• D. The Total Amount of Energy Increases.

Answer: (C)

In a chemical reaction, matter cannot be created or destroyed; atoms are rearranged into new substances, but the total mass stays the same in a closed system. That means the statement that the total amount of matter stays the same best captures the Law of Conservation of Mass. For example, burning a fuel in a sealed container will produce products whose mass equals the mass of the fuel plus the reactant gases—nothing vanishes or appears out of nowhere. The idea that matter is destroyed or that energy must increase doesn’t align with the law. New substances can form, but the total mass remains constant, while energy can change forms.