Students are often presented with the finished MO correlation diagrams of molecules like bis benzene chromium or ferrocene in classes and in organometallic chemistry text books. This activity helps them match the ligand group orbitals of the two benzene rings with the metal valence orbitals. Their understanding and appreciation of such diagrams is significantly enhanced when they find out how only some matches have the appropriate symmetry requirements.

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.