Which of the following statements best represents the law of conservation of mass?

• A. The total mass of reactants equals the total mass of products in a chemical reaction.
• B. Mass can be created or destroyed during a chemical reaction.
• C. The mass of the products is always greater than the mass of the reactants.
• D. Energy and mass are always conserved together in every chemical reaction.

Answer: (A)

Verified step by step guidance

1. Understand that the law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction.
2. Recognize that this means the total mass of the reactants before the reaction must be equal to the total mass of the products after the reaction.
3. Evaluate each statement by comparing it to this principle: the correct statement must reflect that the mass remains constant during the reaction.
4. Identify that the statement 'The total mass of reactants equals the total mass of products in a chemical reaction' directly expresses the law of conservation of mass.
5. Note that other statements either contradict this law or introduce concepts (like energy conservation) that are related but not the focus of this specific law.