According to the Law of Conservation of Mass, what happens to the total mass of substances during a chemical reaction?

• A. The total mass fluctuates randomly.
• B. The total mass remains unchanged.
• C. The total mass decreases.
• D. The total mass increases.

Answer: (B)

Verified step by step guidance

1. Understand the Law of Conservation of Mass, which states that mass cannot be created or destroyed in a chemical reaction.
2. Recognize that during a chemical reaction, atoms are rearranged to form new substances, but the total number of atoms remains the same.
3. Since the number of atoms and their masses remain constant, the total mass of all substances before and after the reaction must be equal.
4. Therefore, the total mass of substances involved in a chemical reaction remains unchanged throughout the process.
5. This principle explains why the correct answer is: The total mass remains unchanged.