A Simple Mnemonic Device for Electron Configuration Anumber of introductory chemistry texts teach electron configuration hy using sho~tcuts.'.~ One shortcut is t o set up a series of parallel columns and cross them with a series of ~ a r a l l earrows l that are ioined from head to tail. A second shortcut uses theUn'+ 1" rule.~heseshortc;tsarefine and workwell in most cases. It is the purpose of this paper to propose an alternate shortcut. The shortcut requires that one be able to draw and label a series of six inverted similar triangles as shown in the figure. Theleft and right sides areexclusively the s and p sides with two d-bases and two d,f-bases. The triangle is read from bottom to top and from left to right. A knowledge that thes, p, d, and f orbitals hold a maximum of 2, 6, 10, and 14 electrons is a necessity. Starting a t the vertex, labelled i s , you follow the left side to the point labelled 2s and read across the base line to the point labelled 2p or the right side. This trend is followed until all of the electrons have been used. The reading may be terminated between sides. The position of the d and f orbitals between sides conforms to the definition of transition. Transition is defined as, a passing from one condition, form, stage, activity, place, etc., to another."
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' Kotz, J. C.; Purcell, K. F. Chemistry and Chemical Reactivity; Saunders: Philadelphia, 1987.
Oxtobv. D. W.: Nachtrieb. N. H. Princioles of Modern Chemistrv: Saunders: Philadelnhia. 1986. Webebste;'~ N& World ~ i e t i o n a r yof the ~ m e r i c o nLanguage, coliege Edition; ~ o r l d 1 9 6 4 . Stanley C. Grenda University of Nevada, Las Vegas Las Vegas, NV 89154
Volume 65
Number 8 ~ u g u s t1988
697
