Students’ Use of Three Different Visual Representations To Interpret Whether Molecules Are Polar or Nonpolar

Visualizing molecular properties is often crucial for constructing conceptual understanding in chemistry. However, research has revealed numerous challenges surrounding students’ meaningful interpretation of the relationship between the geometry and electrostatic properties of molecules. This study explored students’ (n = 18) use of three visual representations of electrostatic potential to interpret whether molecules are polar or nonpolar. The representations consisted of red and blue “lobes” (termed RB) indicating regions of negative and positive potential, a color gradient mapping electrostatic potential on a molecular surface (MAP), and a rendering of the interface between regions of positive and negative potential (ISO). Data on students’ accuracy, time-on-task, and evaluation related to the three visual modes were collected via a Web-based questionnaire. ANOVA indicated that students were significantly more accurate in interpreting ISO representations, although almost half evaluated this mode as the most difficult to use. Furthermore, students took significantly longer to interpret complex molecules than simple molecules using ISO and RB. The results indicate that there may be possible pedagogical benefits in using unconventional visual representations that reduce visual complexity by making molecular relationships explicit. Hence, this has implications for future work on the role of cognitively mapping between different instructional visualizations in the development of fundamental chemical concepts.