Students' Use of Magnetic Models to Learn Hydrogen Bonding and the Formation of Snowflakes

Magnetic molecular models help students explore molecularstructuresand interactions. In this study, we investigated how pairs of studentsused magnetic models to explore hydrogen bonding and the 6-fold symmetryof snowflakes. Fourteen first-year students enrolled in a chemistryunit participated in pairs. Students' interactions with themagnetic models and their peers were video recorded and later transcribed.Students' hand-drawn diagrams, verbal explanations, and gestureswere used to evaluate students' conceptual understanding. Studentsshowed distinctly different patterns of interaction depending on theirprior knowledge of hydrogen bonding and how they socially interacted.Pairs with alternative prior understanding of hydrogen bonding reliedon prompts while using magnetic models to feel the attraction andrepulsion between two water molecules. They then constructed a tetrahedralstructure and discussed its similarities with the branches of snowflakes.Pairs with a better understanding of hydrogen bonding interacted morewith each other, used magnetic models to create ring structures, andexplained their similarities with the 6-fold symmetry of snowflakes.Despite gaining a new understanding of hydrogen bonding, most studentpairs' explanations did not extend to the massive 3D expansionof molecular structures to form a snowflake. Educators should considerthe affordances of magnetic models and students' group dynamicswhen teaching molecular interactions to explain macroscopic-levelphenomena.