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The Chemical Educator
ISSN: 1430-4171 (electronic version)
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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