## CHM 501 Lecture

**Symmetry and Group Theory**

Symmetry is associated with the idea that certain geometrical transformations leave an object unchanged. The geometric operations that do this for molecules are called symmetry elements or symmetry operations. The set of all symmetry elements associated with a molecule obeys the properties associated with a mathematical group so the mathematics of group theory can be applied to molecules. This math allows us to characterize and label some properties of molecules such as molecular orbitals or spectroscopic transitions. In this course, we will use group theory to label molecular orbitals, which will be used to construct molecular orbital diagrams and understand bonding in molecules.