National Center for Learning & Teaching (NCLT)

Atomic Structure as a Threshold Concept

To better illuminate the conceptual barriers to learning atomic structure, this study explores the difficulty students have in understanding this fundamental scientific concept.

Park, E-J., & Light, G. (2009). Identifying atomic structure as a threshold concept: Student mental models and troublesomeness. International Journal of Science Education, 31(2), 233-258. (Link to publisher website)

Atomic Structure as a Threshold Concept

Atomic theory, or the nature of matter, is a principal concept in science and science education. However, students often have great difficulty understanding this concept and the subsequent many alternative models that followed it.

To better understand students' difficulty in learning atomic structure, this study explores the troublesome nature of this fundamental scientific concept. We chose three high-achieving students from an original interview sample of 20 students who were selected from an introductory college chemistry course, and compared pre- and post-course interview responses. Our findings suggest atomic structure as a possible threshold concept for further study in science.