This in-class activity is designed to give general chemistry students practice with drawing Lewis structures. Small groups of 3-5 students compete for points by creating hypothetical molecules that meet criteria (numbers of elements and atoms) assigned by the professor. Beginning with simple molecules, the basic challenge format calls for increasingly complex criteria in successive rounds of competition. One optional variation also allows student groups to challenge each other for bonus points.

Students are asked to find a coordination complex in the recent literature and analyze its structure. This homework or in-class activity is a great way for the instructor to crowd source the discovery of interesting new complexes to use as material in future exams.

In this exercise, students are introduced to Mercury, a program for visualizing and analyzing crystal structure data.  Students are guided through opening the program for the first time and viewing a structure from the Teaching Subset, a selection of structures from the Cambridge Crystallographic Database (CSD). Activites include changing the representation of the complex, moving the structure around the window, accessing information about the structure, and measuring bond lengths and angles within the structure.