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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...

To help in interpreting the polarity of a molecule, charge separation can be visualized by mapping the electrostatic potential at the van der Waals surface using a color gradient or by indicating positive and negative regions of the electrostatic potential using different colored isosurfaces. Although these visualizations capture the molecular charge distribution efficiently, using them to deduce overall polarity requires students to engage in the potentially demanding process of interpreting the relative positions of electron-rich and electron-poor areas. We present a visual tool that could help students assign polarity by exploiting the unique topography of the interface between negative and positive regions of electrostatic potential surrounding a molecule. Specifically, the tool renders the electrostatic potential isosurface(s) of a molecule obtained when the isovalue is set at 0. Examples of polar and nonpolar molecules are discussed.