Unpacking the meaning of the mole concept for secondary school teachers and students

The "mole" is a fundamental concept in quantitative chemistry, yet research has shown that the mole is one of the most perplexing concepts in the teaching and learning of chemistry. This paper provides a survey of the relevant literature, identifies the necessary components of a sound understanding of the mole concept, and unpacks and presents these components in the form of a concept map. The concept map incorporates the atomic-molecular concept with the mole concept, and connects the two concepts by two linking ideas: the number aspect of the SI definition (linking idea 1) and the connection between relative atomic-molecular mass and molar mass (linking idea 2). This concept map not only provides a conceptual framework for making meaning in relation to the mole but also sheds some light on how the concept might be better taught and learned.