Question

which statement describes the law of conservation of mass?
matter is neither lost nor gained during a chemical change
the mass of the products is always less than the mass of the materials that react in a chemical change
the mass of the products is always greater than the mass of the materials that react in a chemical change
a certain mass of material must be present for a reaction to occur

Explanation:

The law of conservation of mass states that in a chemical reaction, matter is neither created nor destroyed. This means the total mass of the reactants equals the total mass of the products.

• The first option “Matter is neither lost nor gained during a chemical change” aligns with this principle.
• The second option “The mass of the products is always less than the mass of the materials that react in a chemical change” is incorrect as it violates the conservation law.
• The third option “The mass of the products is always greater than the mass of the materials that react in a chemical change” also violates the conservation law.
• The fourth option “A certain mass of material must be present for a reaction to occur” is not related to the law of conservation of mass which is about mass equality before and after a reaction, not about the requirement of a specific mass for a reaction to start.

Answer:

Matter is neither lost nor gained during a chemical change