VSEPR theory

Would you like to take a walk with me through the chemical winter wonderland of snowflakes? Well, we chemists know that the stunning six-sided symmetry of snowflakes (Figure 1) results from repeated arrangement of water molecules into a hexagonal crystal structure (Figure 2).

I have been working with the Alchemie team -- founded by a former chemistry teacher, Julia Winter -- for a number of years. Trying out their learning tools for chemistry, giving feedback, and generally brainstorming new ideas for chemistry instruction. 

Teaching VSEPR theory presents some unique challenges for students - particularly picturing molecules in 3-D space. I have found manipulatives to be a powerful tool to help students visualize 3-D molecules. Here are some of my favorite manipulatives for teaching VSEPR and cheap at-home modifications for virtual learners.

Last year, I taught Valence Shell Electron Pair Repulsion (VSEPR) theory and then had the students complete the pHET simulation called Molecule Shapes.

If you look at any chemistry textbook, you will see Lewis structures introduced long before electronic and molecular geometries. This makes sense since you need Lewis structures to determine molecular geometry.