Students' mental models of atomic spectra

Mental modeling, which is a theory about knowledge organization, has been recently studied by science educators to examine students' understanding of scientific concepts. This qualitative study investigates undergraduate students' mental models of atomic spectra. Nine second-year physics students, who have already taken the basic chemistry and chemistry laboratory application courses, participated in the study. Semi-structured interviews were conducted with the participants. The analysis revealed that students had four types of coherently organized knowledge structures: the Scientific Model of Atomic Spectra (SMAS), the Primitive Scientific Model of Atomic Spectra (PSMAS), No Photon Model (NPM), and the Orbit Model (OM). Identified mental models indicated that students used some fundamental concepts interchangeably, and "electronic transition'' and "photon energy'' were the threshold concepts for students' scientific understanding of atomic spectra.