Convenient Chemical Symbols to Illustrate Electronic Excited States

Abstract

The problem of poor comprehension of electronic spectra by chemistry students in upper level undergraduate classes is addressed by consistent application of vector addition to both spin and angular momentum. Using the upgraded box‐and‐arrow diagrams, both atomic and molecular electronic states may be described without the use of advanced mathematics. Simple chemical symbols and formulas are suggested for molecular excited states that complement the existing physical/mathematical notation. Elements of a suitable classroom presentation are presented.

Keywords:

• Electronic spectra
• spectroscopy term symbols
• spin
• student learning

Acknowledgments

The author is grateful to Dr. Andrei N. Vedernikov (University of Maryland), Dr. Mark R. Hoffmann, K. Carlson, and N. Forlemu (UND Chemistry Department) for providing critical comments and help with Figures.

Notes

The author was invited to contribute this paper to a special issue of the journal entitled “Undergraduate Research and Education in Spectroscopy.” This special issue was organized by Associate Editor David J. Butcher, Professor of Chemistry at Western Carolina University, Cullowhee, North Carolina, USA.