Threshold Concepts in Chemistry: The Critical Role of Implicit Schemas

Threshold concepts are conceived as cognitive portals to new and previously inaccessible ways of thinking in a domain. They are transformative, integrative, irreversible, and troublesome Concepts that open the door to highly productive ways of thinking in a discipline. Mastering threshold concepts in chemistry demands the construction of diverse cognitive elements, including implicit schemas that guide and constrain how students think about chemical substances and processes. The central goal of this paper is to highlight five critical shifts in students' implicit schemas that should be fostered to support mastery of major threshold concepts in chemistry.