We have used backward design to develop a first-year laboratory-based course centered on the development of a meaningful understanding of intermolecular forces, a challenging topic that has been identified as a threshold concept. Deep understanding of this concept requires students to integrate thinking at all three levels of representation identified in the Johnstone triangle: the observable (macroscopic) level, the molecular (particulate) level, and the representational or symbolic level. In order to help students navigate these three levels of chemical thinking, we focus on three elements of threshold concepts in our teaching: conceptual, epistemological (disciplinary practices), and ontological (mental models).

We use collaboration, iteration, close observation and analysis of student work, and chemical education research to guide our curricular approach. We have developed experiences, activities, and assessment practices that scaffold student learning and allow us to identify certain steps on the path students follow as they cross (or do not cross) this important conceptual threshold. We will share our framework for helping students move from thinking like novices to thinking like experts on the topic of intermolecular forces and how this might be transferred to other threshold concepts.

In this workshop, participants will work in groups to develop laboratory exercises to help students cross the threshold and gain a deep understanding of intermolecular forces. Facilitators will share our experiences integrating Johnstone’s triangle to aid students in developing a nuanced model of this challenging concept. Participants will leave with a newly drafted or revised laboratory activity involving intermolecular forces within their curriculum that takes a more deliberate approach to scaffolding student learning on their journey towards thinking like an expert. This template will prepare participants to develop additional laboratory activities addressing threshold concepts within their own curriculum.