Which statement best represents the law of conservation of mass with regard to chemical reactions?

• A. Matter can be created or destroyed during a chemical reaction.
• B. The number of atoms changes during a chemical reaction.
• C. The mass of the products is always greater than the mass of the reactants.
• D. The total mass of reactants equals the total mass of products in a chemical reaction.

Answer: (D)

Verified step by step guidance

1. Understand the law of conservation of mass: it states that mass cannot be created or destroyed in a chemical reaction.
2. Recognize that during a chemical reaction, atoms are rearranged but the total number of atoms remains constant.
3. Realize that because atoms are neither created nor destroyed, the total mass of the reactants must equal the total mass of the products.
4. Evaluate each statement in the problem to see if it aligns with this principle: only the statement that says 'The total mass of reactants equals the total mass of products in a chemical reaction' correctly represents the law.
5. Conclude that the correct representation of the law of conservation of mass is that the total mass before and after a chemical reaction remains the same.