Background:
This study examines the pre-service teachers’ opinions about conceptual integration (CI) and their understanding of it. The CI studies in the literature are mainly in understanding chemistry concepts at college and university levels, and these studies are often on a specific chemistry concept. Also, even there are studies about the CI in which physics pre-requisite knowledge is used for teaching chemistry concepts, there are no much more studies about the CI in which chemistry pre-requisite knowledge is used for teaching physics concepts.

Material and methods:
Data was collected through in-depth semi-structured interviews comprising ten guiding questions. Three pre-service physics and three pre-service chemistry teachers participated conveniently in the study. While the pre-service chemistry teachers took a course regarding the CI explicitly taught, the pre-service physics teachers were not subjected to any information relating to the CI in their course. Data was analyzed by forming the codes and themes.

Results:
Generally speaking, while the pre-service chemistry teachers think that physics concepts should be used in the chemistry lessons, the pre-service physics teachers believe that these two subjects’ concepts generally are not related to each other.

Conclusions:
Moreover, the participants had some difficulties in understanding the CI between physics and chemistry concepts.