This is a short critical thinking exercise that I use to assess whether my students have understood where the d orbital splitting in Octahedral and Tetrahedral geometry  comes from.  I do it at the beginning of the class after we discuss CFT/LFT in Oh and Td compounds. 

This is a truly hands-on activity in which students manipulate paper cutouts of carbon atomic orbitals and oxygen group orbitals to identify combinations with identical symmetry and build the carbon dioxide molecular orbital diagram. The activity pairs well with the treatment of MO theory in Miessler, Fischer, and Tarr, Chapter 5. An optional computational modeling component can be added at the end.

In this activity, a pair of students are show an object or molecule and are asked to determine the point group before their competitor.

Students work in groups to identify relevant steps and intermediates in 3 catalytic cycles, all the while considering bonding (and electron counting) factors.  Following assignment of these steps and intermediate species, the students consider several questions related to catalysis more broadly, particularly the role of each reagent, how to speed up or slow down specific steps, and the importance of regiospecificity in certain steps.