How Do Inorganic Students and Instructors Describe Conductivity in Solids?

This study investigates how inorganic chemistry students and faculty discuss electrical conductivity differences between a metal and a semiconductor using an open-ended question with temperature-dependent conductivity data. The question was deployed across seven foundation-level inorganic chemistry courses in different institutional contexts. Four overarching categories of ideas emerged from the responses: conductivity, doping, band structure, and the effects of temperature. Responses were analyzed on the basis of these categories. The majority of students discussed conductivity and doping, with fewer discussing the band structure and temperature. Students enrolled in courses with a physical chemical prerequisite referenced more ideas, including more submicroscopic ideas, in their responses compared to students in a course that did not have this prerequisite. Instructor responses included ideas from all four categories as well as more ideas derived from submicroscopic models. This pattern is consistent with experts referring to more resources than novices. Generally, these results provide further evidence of the impact that increased exposure and practice have on learning and development of knowledge. These findings reveal that, although students use ideas from the four overarching categories, they do not fully use those concepts to explain the electronic behavior of solids, which suggests the need for instruction that helps students make connections between macroscopic data and submicroscopic explanations. The resources used by inorganic students and suggestions for how these ideas can be surfaced and integrated during instruction are presented herein.