Examining a Successful PhET-Based Laboratory Activity for Molecular Geometry and Molecular Polarity

Abstract Molecular geometry and molecular polarity are foundational topics in general chemistry, yet students often struggle with three-dimensional visualization, spatial reasoning, and the interpretation of multiple molecular representations. To support student learning of these concepts, a laboratory activity was developed using the PhET Molecule Shapes and Molecule Polarity sims. The activity combines guided inquiry, interactive simulations, physical molecular models, and an individual laboratory practical to help students connect Lewis structures, electron-domain geometry, molecular geometry, bond polarity, and molecular polarity. The activity has been implemented for approximately a decade in a large-enrollment first-semester general chemistry laboratory course. Evaluation data collected through end-of-semester student surveys over a three-year period indicated that students identified the activity as one of the laboratory experiences that most strongly supported their learning. Student comments frequently highlighted the value of visualization provided by the simulations and the role of the laboratory practical in reinforcing understanding. The activity and supporting materials are provided as a resource for instructors seeking to support student learning of molecular geometry and molecular polarity using PhET sims.