Others have said that metaphors are pervasive in, and indispensable to, scientific practice. If one accepts this claim, it is important to ask what the consequences might be of failing to recognize that a given scientific assertion, or scientific model, is metaphorical rather than literal. Following a discussion of the relationship between metaphors and models, we pursue this point in the discipline of chemistry and ask what happens when students of chemistry fail to recognize the metaphorical status of certain models and interpret them literally. How does this affect their conception of chemical phenomena? We examine three cases to show where conceptions might differ and why it is imperative that we care about how these differences are generated. We conclude with general implications for teaching. (Nalini Bhushan and Stuart Rosenfeld)