Final answer:
The correct response to the question is 'B) The total mass of carbon and oxygen in CO remains constant during chemical reactions', as dictated by the law of conservation of mass, which is integral to Dalton's atomic theory.
Step-by-step explanation:
According to Dalton's atomic theory, the law of conservation of mass applies to CO (carbon monoxide) and all other substances in chemical reactions. This law asserts that the total mass of reactants must equal the total mass of products after a chemical reaction occurs. Therefore, the correct response to the student's question would be: B) The total mass of carbon and oxygen in CO remains constant during chemical reactions.
For instance, if we have a carbon atom with a mass of 12 units and an oxygen atom with a mass of 16 units, the CO molecule they form would have a mass of 28 units. In a reaction where CO is produced from carbon and oxygen, for every 12 units of carbon and 16 units of oxygen consumed, 28 units of CO are produced, illustrating that mass is conserved.
The idea that mass is neither created nor destroyed in a chemical reaction is a cornerstone of chemistry.