Which statement correctly describes the law of conservation of mass in chemical reactions?

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Multiple Choice

Which statement correctly describes the law of conservation of mass in chemical reactions?

Matter is conserved in chemical changes: the atoms you start with are the atoms you end up with, just rearranged. In a closed system, the total mass before a reaction equals the total mass after. This is why the statement that matches the law of conservation of mass is that the reactants’ mass equals the products’ mass. The idea that mass is created or destroyed or that mass always decreases (or increases) with energy release doesn’t fit ordinary chemistry, where mass remains the same to a very good approximation. Any tiny mass change from energy release is far too small to notice in typical chemical reactions.

Matter is conserved in chemical changes: the atoms you start with are the atoms you end up with, just rearranged. In a closed system, the total mass before a reaction equals the total mass after. This is why the statement that matches the law of conservation of mass is that the reactants’ mass equals the products’ mass. The idea that mass is created or destroyed or that mass always decreases (or increases) with energy release doesn’t fit ordinary chemistry, where mass remains the same to a very good approximation. Any tiny mass change from energy release is far too small to notice in typical chemical reactions.

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