According to the Law of Conservation of Mass, what happens to the atoms of the reactants during a chemical reaction?

• A. They disappear completely from the system.
• B. They are destroyed and replaced by new atoms.
• C. They combine to form energy, resulting in a loss of mass.
• D. They are rearranged to form new substances, but their total number remains unchanged.

Answer: (D)

Verified step by step guidance

1. Recall the Law of Conservation of Mass, which states that mass cannot be created or destroyed in a chemical reaction.
2. Understand that atoms are the fundamental units of matter and during a chemical reaction, these atoms are neither lost nor gained.
3. Recognize that the atoms in the reactants are rearranged to form new substances called products.
4. Note that although the atoms are rearranged, the total number of each type of atom remains the same before and after the reaction.
5. Conclude that the mass of the reactants equals the mass of the products because the atoms are conserved and only their connections change.