Thursday, July 12, 2007

Should the Bohr Model be Taught in Schools?

This preprint explores this question. More specifically, it studies the students' knowledge of the atom after being taught both the Bohr Model and the Schrodinger's model.

Abstract: Some education researchers have claimed that we should not teach the Bohr model of the atom because it inhibits students' ability to learn the true quantum nature of electrons in atoms. Although the evidence for this claim is weak, many have accepted it. This claim has implications for how to present atoms in classes ranging from elementary school to graduate school. We present results from a study designed to test this claim by developing curriculum on models of the atom, including the Bohr and Schrodinger models. We examine student descriptions of atoms on final exams in transformed modern physics classes using various versions of this curriculum. We find that if the curriculum does not include sufficient connections between different models, many students still have a Bohr-like view of atoms, rather than a more accurate Schrodinger model. However, with an improved curriculum designed to develop model-building skills and with better integration between different models, it is possible to get nearly all students to describe atoms using the Schrodinger model. In comparing our results with previous research, we find that comparing and contrasting different models is a key feature of curriculum that helps students move beyond the Bohr model and adopt Schrodinger's view of the atom. We find that understanding the reasons for the development of models is much more difficult for students than understanding the features of the models. We present new interactive computer simulations designed to help students build models of the atom more effectively.

I think the Bohr model should be taught if nothing else, for historical context. However, as the authors have pointed out, it isn't the subject matter that is the source of the problem here, it is HOW they are taught, and how these models are integrated into the teaching of the material. I think many instructors do not emphasize clearly enough that the Bohr model is valid only in the historical sense. More important than the actual understanding of what a Bohr model is, is the story on how physics develops. It clearly shows an example on how we develop our understanding of something new, where we try out an initial model that may nor may not be accurate, but somehow manages to agree roughly with experiment. It is only upon refinement after refinement that we arrive at some degree of a valid description of a phenomenon. The Bohr model is invaluable in this historical perspective.


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