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Preface

The main difficulty in teaching chemistry lies in the explanation of chemical phenomena on the basis of quantum chemistry — when the teachers have to explain things that they hardly understand themselves. The widely used quantum chemical explanations include paradigms and principles whose physical bases are unclear.

The Lewis rules, widely employed to explain chemical bonding phenomenon at the introductory level, have unclear physical reasoning and multiple exceptions.

The general character of all the explanations of chemical phenomena in the existing textbooks — first of all, the quantum-chemical explanations—does not leave any doubt in the students that at least such phenomena as wave properties of particles and delocalized electrons actually exist, that there are atoms and molecules in the orbitals where only electrons can be situated, and that these orbitals can hybridize.

The fact that quantum-chemical explanations, given in chemistry textbooks, are actually fabrications of the authors, has been admitted in one of the main textbooks "Quantum Chemistry" that were reissued five times from 1970 to 2004 by Ira Levine. Thus, in the first edition, 1970, on page 559 we read: "There is a tendency to consider 'configuration interaction', 'hybridization', etc. as real physical phenomena. Such concepts are only artifacts of the approximations used in the calculations. Even the concept of orbitals is but an approximation, and strictly speaking, orbitals do not exist."

In the fifth edition (2004) on page 609 we read: "The difference between the energy for the individual structure I and that found when all VB structures are included is the resonance energy of benzene. One says that benzene is "stabilized by resonance," but, of course, resonance is not a real phenomenon."

Such concepts as "configuration interaction," "resonance," "hybridization" and "exchange" are not real physical phenomena, but only artifacts of the approximations used in the calculations. Likewise, the concept of orbitals is but an approximation, and, strictly speaking, orbitals do not exist.

That is, in accordance with quantum chemistry, all the explanations based on such logic of the students as realistic physical phenomena accepted as orbitals, resonance, exchange, hybridization, etc., are related to false knowledge, which, as we all know, is worse than the lack of knowledge.

According to J.N.Spencer (JCE No. 3 p. 182 1991) 'the basics of quantum-chemical interpretations are unteachable'.

When making his report at the 225th meeting of the ACS at New Orleans, just to amuse of the listeners a bit, Spencer offered examples of quantum-chemical interpretations taken from traditional textbooks. The listeners reacted most lively, and heartily applauded the speaker. This undoubtedly proved the truth of the well-known premise:

            When mankind laughs, it parts with its misconceptions.

The main difficulties in explaining chemical bonding and chemical reactions lie in the fact that this problem had never been solved by science in the previous century.

J.Ogilvie wrote: "What is the status of the chemical bond in 1990? We know what it is not: a stick between two balls —as the organic chemists of the 19th century might have imagined. It is certainly not orbitals. If we know what the nature of a chemical bond is not, can we state what the nature of the chemical bond is?" [JCE, 1990, 67, 280]     

Richard Feynman, winner of a Nobel Prize for physics, asked: "If you had only one sentence with which to pass the most important scientific knowledge we possess, on to the next generation, what would that sentence be? Feynman's own answer was: "Everything is made of atoms." 

Feynman went on: "But what is their size and shape?" the next generation might ask, "And how do they stick together?" [Colin J.Humphrey, NATURE, September 1999 #401 p.21.]

As we see, R.Feynman had made a prophetic prediction.

According to S.Lippard (C&EN, Aug. 7, 2000), as a result of the recent revolutionary changes in chemistry, older paradigms have been giving way to new principles.

In part the paradigm related to the problem of chemical bonding (see V.&Y.Gankin's — How Chemical Bonds Form and Chemical Reactions Proceed, 1998) that can be solved only in the framework of quantum mechanics (relative to the supposition that the electron is a particle-wave) was exchanged for a paradigm stating that this problem can be solved without the wave properties of the electron, i.e., in the framework of the classical phenomenological approach, in whose framework the problem of the atom's layer-like structure and the physical essence of the periodic law were previously solved.

In the course of the chemical revolution, answers to questions like 'How do atoms stick together?' and 'How do chemical reactions proceed?' allowed transiting to changes in the interpretation of the main chemical phenomena: atom structure, periodic law, chemical reactions, catalysis, cause-and-effect connections between these phenomena, and relatively, the cause-and-effect links between micro-world (atoms, molecules), macro-world (solid bodies), and, what is most important for education — to make these explanations really teachable.

  

BRIEF HISTORY: REFOCUSING THE GENERAL CHEMISTRY CURRICULUM

In 1990 the ACS Division of Chemical Education formed the Task Force on the General Chemistry Curriculum as follows:  

Task Force Members: Stephen Berry (University of Chicago), George Bodner (Purdue University), Orville Chapman (UCLA), William [Flick] Coleman (Wellesley College), Arthur Ellis (University of Wisconsin at Madison), John Fortman (Wright State University), Ron Gillespie (McMaster University), Stephen Hawkes (Oregon State University), Dudley Herschbach (Harvard University), Herbert Kaesz (UCLA), Joseph Lagowski (University of Texas at Austin), Ram Lamba (Inter American University of Puerto Rico), David MacInnes (Guilford College), Patricia Metz (Texas Tech University), Jerry Mohrig (Carleton College), Karen Morse (Utah State University), Lyman Rickard (Millersville University), Ethel Schultz (National Science Foundation), James Spencer, Task Force Chair (Franklin & Marshall College), Jeffrey Steinfeld (Massachusetts Institute of Technology), Judith Strong (Moorhead State University), Tamar [University] Susskind (Oakland Community College), Hessy Taft (Educational Testing Service).  

Task Force Resource Group: Theodore Brown (University of Illinois), Ernest Eliel (University of North Carolina), Clark Fields (University of Northern Colorado), Baird Lloyd (Emory & Henry College), Joseph Morse (Utah State University), Alan Pribula (Townson State University).

Chapter 1.Preface
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