Connecting geometry and chemistry: A three-step approach to three-dimensional thinking

摘要

A three-step active-learning approach is described to enhance the spatial abilities of general chemistry students with respect to three-dimensional molecular drawing and visualization. These activities are used in a medium-sized lecture hall with approximately 150 students in the first semester of the general chemistry course. The first activity involves using clay and sticks to help students visualize and overcome common misconceptions about geometric figures; the second activity involves connecting geometric figures with molecular shapes to foster an appreciation of the space that molecules fill; and the final activity is to introduce the more abstract valence shell electron pair repulsion theory using plastic, traditional molecular models to demonstrate how to represent molecules spatially on paper. The three activities can be done in three 55-min lectures with plenty of time for discussion.