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The Chemical Educator

ISSN: 1430-4171 (electronic version)

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Abstract Volume 25 (2020) pp 88-91

Orbital Shaped Standing Waves Using Chladni Platess

Eric Janusson, Johanne Penafiel, Shaun MacLean, Andrew Macdonald, Irina Paci* and J. Scott McIndoe*

Department of Chemistry, University of Victoria, P.O. Box 3065 Victoria, BC V8W3V6, Canada, ipaci@uvic.ca, mcindoe@uvic.ca
Received December 3, 2019. Accepted February 5, 2020.

Published: 6 May 2020

Abstract. Chemistry students are often introduced to the concept of atomic orbitals with a representation of a one-dimensional standing wave. The classic example is the harmonic frequencies, which produce standing waves on a guitar string; a concept that is easily replicated in class with a length of rope. From here, students are typically exposed to a more realistic three-dimensional model, which can often be difficult to visualize. Extrapolation from a two-dimensional model, such as the vibrational modes of a drumhead, can be used to convey the standing wave concept to students more easily. We have opted to use Chladni plates, which may be tuned to give a two-dimensional standing wave that serves as a cross-sectional representation of atomic orbitals. The demonstration, intended for first year chemistry students, facilitates the examination of nodal and anti-nodal regions of a Chladni figure that students can connect to the concept of quantum mechanical parameters and their relationship to atomic orbital shape.

Key Words: Laboratories and Demonstrations; physical chemistry

(*) Corresponding author. (E-mail: mcindoe@uvic.ca)

Article in PDF format (173 KB) HTML format

Supporting Materials:

Additional information concerning materials, equipment, and experimental settings, as well as several photos and a video of standing wave patterns generated on the square and circular Chladni plates, may be found within the supporting material. (4170 KB)



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