Which law states that matter cannot be created or destroyed?

• A. Physical Change
• B. Chemical Change
• C. Law of Conservation of Matter(Mass)
• D. Reactant

Answer: (C)

The idea being tested is that matter cannot be created or destroyed; it can only change form. This is captured by the Law of Conservation of Mass, which says that in a closed system the total mass before a process equals the total mass after. Matter may undergo physical changes (like ice melting) or chemical changes (like iron rusting), but the overall amount of matter stays the same. For example, in a sealed container, the mass of the reactants that go into a reaction equals the mass of all products that come out, even if substances are rearranged or transformed. That’s why this law is the best choice—it states the universal rule about matter. The other terms describe types of transformations or starting substances, but they don’t express the principle that mass is preserved.