A method of determining the correct molecular geometry of simple molecules and ions with one central atom is proposed. While the usual method of determining the molecular geometry involves first drawing the Lewis structure, this method can be used without doing so. In fact, the Lewis structure need not be drawn at all. The Lewis structure may be drawn as the final step, with the geometry of the simple molecule or ion already established. In the case of diatomic molecules, any atom may be used as the central atom. When hydrogen is present in a multiatom molecule or ion, this method "naturally" eliminates choosing hydrogen; but, any other atom may be used as the central atom to determine the correct geometry. The Lewis structure can then be used to determine the formal charges on the atoms. In this way there is a check on the selection of the central atom, should the correct Lewis structure be desired. Thus, it assumes that one is familiar with both Lewis structures and the valence shell electron pair repulsion (VSEPR) approach to bonding. The approach suggested in this paper will give rapid and accurate molecular geometries, and it is fun !!!
More Information
Citation
Gomba, Frank J. J. Chem. Educ.1999 76 1732.
Keywords
Introductory / High School Chemistry; Teaching / Learning Aids; Bonding Theory; Molecular Properties / Structure
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.