University physics students' use of models in explanations of phenomena involving interaction between metals and electromagnetic radiation

We examine third year university physics students' use of models when expla ining familiar phenomena involving interaction between metals and electroma gnetic radiation. A range of scientific models are available to explain the se phenomena. However, explanations of these phenomena tend not to be used as exemplars of scientific models within undergraduate physics education. T he student sample is drawn from six universities in UK and Sweden. These st udents have difficulties in providing appropriate explanations for the phen omena. Many students draw upon the Bohr model of isolated atoms when explai ning light emission of metals. The students tend not to recognize that atom s in metals interact to give an electronic structure very different from th at of the isolated atom. Few students use a single model consistently in th eir explanations of these related phenomena. Rather, students' use of model s is sensitive to the context in which each phenomenon is presented to them .