Design of a structure model set for inorganic compounds based on ping-pong balls linked with snap buttons

Abstract

Structure model sets for inorganic compounds are generally expensive; their distribution to all students in a class is therefore usually impractical. We have therefore developed a structure model set to illustrate inorganic compounds. The set is constructed with inexpensive materials: ping-pong balls, and snap buttons. The structure model set can be used to illustrate isomerism in coordination compounds and periodic structures of ceramic perovskites. A hands-on activity using the structure model set was developed for high school students and was well-received by them. Despite the concepts being slightly advanced for them, the students’ retention of the knowledge gained through the activity was tested a week after they completed the activity and was found to be relatively high, demonstrating the usefulness of the activity based on the structure model set.

Reusing Waste Plastic Caps to Build Inexpensive and Easily Changeable Crystal Structure Models

“…At least seven students said they wanted to build similar models at home. Overall, these results suggest that the modeling activity in an active learning environment plays an indispensable role in actualizing the teaching value and full potential of the cap-and-stick model, which is consistent with the reported increase in students’ learning outcomes through modeling activities. ,,,,, …”

“…The reported transparent ball-based models with close-packed structures show the formation of interstices more clearly than the cap-and-stick model; however, the positions and coordinates of the interstices are difficult to calculate. This is one of the most remarkable features of the cap-and-stick model compared with other 3D models. − ,,− …”

“…Setting the length of the triangle’s sides (Figure B) to 12.3 cm results in a 10 cm layer distance, which facilitates the height calculations of tetrahedral/octahedral interstices. Compared with previously reported 3D models in studying crystal structures, − ,,− the cap-and-stick model is extremely useful for understanding the coordinates of atoms/interstices, lattice structure, unit cells, and packing arrangements.…”

“…Visualizing the properties of a crystal with 3D structural features is a conventional approach to studying crystal structures. − Examples used for such a purpose typically include 2D illustrations in textbooks, 3D object-based models, − and 3D structures animated by computer software. , The multiple developed 3D object-based models ideally characterize the crystal structure features, such as lattice structure, − unit cell, ,,− coordination number, ,,, site occupation, etc. and are commonly employed for visualizing and teaching crystal structures in the classroom.…”

“…and are commonly employed for visualizing and teaching crystal structures in the classroom. However, the reported 3D object-based models require either professional materials or manual dexterity in construction, − ,− which limits the widespread use and students’ participation in the modeling activity. Plastic caps, a kind of ubiquitous waste with various colors and dimensions, are promising materials for building 3D models in chemistry; however, the reported processes used to combine and fix the caps to build molecular models are too complex and time-consuming. , Another challenge in building crystal models is the easy transformation from one structure to another, which will significantly improve the utilization value of materials.…”