Teaching crystal structures using a transparent box with tennis balls

In this essay we describe how we designed and implemented a class discussion session on the concepts of crystal structure where students are required to create a wide variety of crystal structuresby stacking tennis balls into a transparent box. The box enabledthem to view the crystal structure from different angles to betterappreciate the appearance of different facets of the crystal. With this approach, the students gained an intuitive, hands-on appreciation of the crystal structures, their geometry and their conventional cubic unit cell. This hands-on practical pedagogical experiment was carried out and repeated over two academic years, during which we surveyed the students with the aim of determining the effectiveness of this approach and identifying areas for improvement. Survey results show that this method was well received by the students and valuable feedback on areas for improvement was also gathered.Possible future extension of this teaching approach is also discussed.