Which statement best describes the law of conservation of mass?

• A. Matter cannot be created or destroyed in a chemical reaction.
• B. Matter can spontaneously appear or disappear during physical changes.
• C. Matter can be converted entirely into energy during a chemical reaction.
• D. The mass of the products is always greater than the mass of the reactants.

Answer: (A)

Verified step by step guidance

1. Understand that the law of conservation of mass states a fundamental principle in chemistry regarding matter during chemical reactions.
2. Recall that this law asserts matter cannot be created or destroyed in an isolated system during a chemical reaction.
3. Recognize that this means the total mass of reactants before the reaction must equal the total mass of products after the reaction.
4. Eliminate options that suggest matter can appear or disappear, or that mass changes in a way that contradicts this principle.
5. Conclude that the correct description is: Matter cannot be created or destroyed in a chemical reaction.