Using Balls of Different Sports To Model the Variation of Atomic Sizes
Gabriel Pinto Universidad Politecnica de Madrid, Departamento de Ingenieria Quimica Industrial, E.T.S.I. Industriales, Jose Gutierrez Abascal 2, 28006 Madrid, SPAIN
In this article, an analogy is described about the order of magnitude of the variation of atomic sizes that can be used for discussion in introductory chemistry classes. The order of magnitude of this variation, involving microscopic magnitudes, is difficult for students to imagine. For the most part, the students are very familiar with the world of sports. In any case for example, the teacher can make use of the wide, informative coverage given to the olympic games or similar events, where different sports are televised in a few days. The radii of official balls for seven well-known sports are given, and students must assign an atom to each ball by using tabulated single-bond, covalent radii and by assigning the smallest ball (i.e., corresponding to ping-pong) to the smallest atom (i.e., hydrogen). The balls can also be used to show how the ionic radii change upon ionization.
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Citation
Pinto, Gabriel. J. Chem. Educ.1998 75 725.
Keywords
Demonstrations, Introductory/High School Chemistry, Teaching/Learning Aids, Atomic Properties/Structure
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