An Inquiry-based approach to the Franck-Hertz experiment

The practice of scientists and engineers is today exerted withininterdisciplinary contexts, placed at the intersections of different research fields, includingnanoscale science. The development of the required competences is basedon an effective science and engineering instruction, which should be able to drivethe students towards a deeper understanding of quantum mechanics fundamentalconcepts and, at the same time, strengthen their reasoning skills and transversalabilities. In this study we report the results of an inquiry-driven learning pathexperienced by a sample of 12 electronic engineering undergraduates engaged toperform the Franck-Hertz experiment. Before being involved in this experimentalactivity, the students received a traditional lecture-based instruction on the fundamentalconcepts of quantum mechanics, but their answers to an open-ended questionnaire,administered at the beginning of the inquiry activity, demonstrated thatthe acquired knowledge was characterized by a strictly theoretical vision of quantumscience, basically in terms of an artificial mathematical framework having very poorconnections with the real world. The Franck Hertz experiment was introduced tothe students by starting from the problem of finding an experimental confirmation ofthe Bohr’s postulates asserting that atoms can absorb energy only in quantum portions.The whole activity has been videotaped and this allowed us to deeply analysethe student perception’s change about the main concepts of quantum mechanics.We have found that the active participation to this learning experience favoredthe building of cognitive links among student theoretical perceptions of quantummechanics and their vision of quantum phenomena, within an everyday context ofknowledge. Furthermore, our findings confirm the benefits of integrating traditionallecture-based instruction on quantum mechanics with learning experiences drivenby inquiry-based teaching strategies.