book reviews by the very nature of the systems considered, the discussion is of limited scope. As Platt has emphasized, these two systems provide us with no insight into the two most important features of chemical affinity: its saturation and its directional character-for the Exclusion Principle has not entered into the problem. The systems are too simple to exhibit structurally interestingfeatures. Evidently it cannot be over-emphasiaed that the proton is a, very speoid case in chemistry. It is the only kernel with no inner-shell electrons. Though stressed by Werner (not mentioned by Pimentel and Spratley) and Lewis (down-graded by P and S), the importance of kernel(or atomic-) sizes (and shapes) in determining the chemistries of the elements receives no systemrstio treatment in this book. The primitive graphic ffomulas given for SO*, SO, and SO?, e.g., bear little relation to known interatomic distances and provide the reader with no clues as to the reasons for the non-existence of FOa- and N04a-. I was troubled, also, by the statement that Plrtnck introduced the "particulate model" of light (hestrenuously opposed, a t first, this extension of his work by Ein: stein); by the implication that the radiusratio rules fit well the observed crystal structures of the alkali halides (approximately 40% of the alkali halides do not obey the simple,~Goldsehmidtradius-ratio rules); by the failure to mention hydrogen-bonding in gaseous hydrogen fluoride in a discussion of dipole moments and heats of vaporization; by the use of the virial theorem (in a discussion of the ionic model) for a system whose (inexact) wavefunction is not allowed to relax (and, thereby, to alter its shape and, correspondingly, the system's kinetic and potential energies) with a change in inter-ionic distance; and by the consistent plscement of hydrogen, the pebble upon which this book is based, in Group I. It might be argued that hydrogen belongs in Group VII andlor Group IV, or in a. Group by itself (vide supra). But in no way does the chemistry of hydrogen, rtnd its bonding in compounds, correspond closely (or, if closely, uniquely) to that of the elements of Group I. Of d l the elements in the Periodic Table, those in Group I are least like hydrogen, except for the charges on their kernels. The hook is relatively free of typ* graphical errors. Several c u p s are missing in Fig. 3-5, however, and several nodal surfaces are missing in Fig. 4-19. In Fig. 4-20 two of the orbitals are mislabelled. A major difficulty with current introductions to the chemical bond that, by dwelling on the hydrogen atom and the hvdro~en-molecule ion, exclude almost everyihing that was l'earned ahout the bond in chemistry prior to 1926 (and include little that has been learned ahout it in quantum mechanics since 1940), is that, with young students, particularly, one must resort frequently to authority. Even in the better treatments, there is a. high density of "telling." At each critical juncture in Pimentel snd Spratley, e.g.,
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appear such phrases as "We find t h a t . . . " and "Quantum mechanics tells us . . . " Often, also, the word "explain" is used where a more accurate word would he "describe," or "rat,ionaliee." What we have is a New Descriptive Chemistry, only now, instead of having to memorize facts that seem important (to the teacher) hut that cannot, at the moment, he related to other facts, it is quantum mechanical terminology, orbital d i e grams, and other approximations that must be memorized. Within its chosen limits, however, this is a superior book. The authors express the hope that teachers as well as students may profit from reading it. I believe they will. I did.
HENRY A. BENT North Carolina State University Raleigh Transition-Metal Organometallie Chemistry: An Introduction
R. Bruce King, University of Georgia, Athens. Academic Press, Inc., New York, 1969. ix 204 pp. Figs. and tables. 15.5 X 23.5 cm. $11.50.
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For over a hundred years the subject of organometallic chemistry embraced only the "representative" elements, or rather those of the "representative" elements which were metals. Perhaps that
