Science and Mythology To the Editor:
The 1989 September issue began, a s is customary, with a thoughtful editorial. I t argued t h a t t h e teaching of chemistry could become a s removed from reality as the teaching of calculus often is. Readers were urged to recognize and counter this trend. This editorial and several of thc articles in the issue leads me to the question: .'T)oes the editor's r~swnslbilitvto the wcll beine of chemical education end with the edi"toria1 page?" Along with the usual assortment of technical articles, there are some articles that speak directly to what should or should not be done in introductory chemistry courses. The emphasis of several of these is incompatible with the goals suggested in the editorial and with the growing movement toward "real-world" or '?lands-on" chemistry. To appreciate the role of these articles, it is helpful to distinguish the teaching of chemistry as a science and the teaching of chemistry as mythology You are teaching chemistry a s a science if what your students learn is the result of their own observations or experiences and their own deductions therefrom. The student must be helped to grow to see that he or she can understand the world, not just that others can understand it. In practice, we can only try to stay a s close as possible to this attitude. We often must substitute diaprams and photographs for direct experiences, and we must guide deductions in profitable directions. But, even when we waver, we can keep in mind: We are teaching a science if what the student learns stems from what he or she knows and sees. You are teaching chemistry a s mythology when you tell your students a story. That route has its seductions and is probably t h e principal way i n which introductory chemistry is now presented. Students, to begin with, find it much easier to be passive listeners of a good story than to strueele.. "hand-to-hand" a s it were. with realitv. Manv trnchcrs i ~ r ewonderful story~~rllcrs, and in chemistry thrrc arc some wonderful dtories. The vuvaec of'IJlvsses in the mythology of the ancient Greeks is nomore amazing than the world of atoms and molecules that chemists tell of. I t does not matter to the listeners t h a t the stories t h a t chemists tell are purported to be true, while those of Homer are not. To the listener, both are wondrous tales that are not based on the listener's own experiences and are not subject to any real or reasonably imagined verification by the listener. Both the stories told in beginning chemistrv courses and the leeeuds of the ancient Greeks are mytgs. Three of the articles in the Seotember issue oromote the teaching of chemistry a s myth. o n e article (ljwould have us tell students that elements are defined by the numbers of protons in the nucleus of atoms. Chemistry would follow after students had been told about the nucleus. protons. neutrons, electrons, atomic number, and mass' number. Students can learn all this, just a s they can learn the great stories of mythology. But, little is part of, or a reasonable extension from, their own experiences. To them, i t is mythology. Defining pure substances and then using reactions to classify them as elements and compounds does present some problems. I n this approach, however, materials can be looked at, and chemical reactions can be carried out. Substances and chemical reactions can he brought into the students'own experiences. A student could be given a piece of sulfur and asked if it were a sample of a pure substance and. if so. if sulfur is a n element or a comoound. He or she could deal with the question in terms o i t h e sample and chemical reactions that mieht occur or mieht not occur. With the atomic-number approach, all the &dent could do
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84
Journal of Chemical Education
is look in a book to see if sulfur is listed a s one of the elements. Another article (2)urges us to replace the ozonelike octet diagrams, 1 and 2, for the bonding in the sulfur dioxide molecule with the expanded-octet, two-double-bond picture 3
If the students are not simply to be told this 'correct" result, they must be led through the arguments given and taught about d orbitals and the structural implications of d, -p, bonding. They would probably find determining the number of angels that could dance on the head of a pin closer to their realities. Students can be guided from their meager knowledge of a few molecules to simole bonding ideas. for examole.. Lewis octets. Bond descriptions and structures can be put toeether for some molecules of the second-row elements. TKc banding in the bent SO, molecule can be mtroduced by the octet wonelike diamams. Then. if expanded-uctets. as in the SF6 molecule, have been i&od&ed, the chargeseparation component of diagram 1 can be replaced by a covalent bond line to give the description in diagram 3. Thus, we can suggest this result without straying too far from the path that the experiences of students allow them to follow. A third article (3) shows how the students can organize the results of atomic spectroscopy to see, for example, that the ground state electron confirmration of the uranium atom is [Rn15fs6d'7s2po,A simpikr result that illustrates the procedure uresented is that the mound state electron coniguration oythe potassium atom ;1 IAr13d04s'4p0. How, one might ask. could a student see that these atomic electronconfig&ations are correct? Even more puzzling is what use such detailed atomic electron confimrations are to the beginning chemistry student. ~ t o m i c & c t r o nconfigurations such as these are some of the most enduring, most beloved, stories in the mythology of introductory chemistry These three articles, which claim to be for introductory chemistry presentations, contribute to the teaching of chemical mvtholow. Thev "helu.to smooth out the storv so that studeits ca&ore easily appreciate this mythofogy. Such articles a r e of interest and value to t h e manv teachers who, fmm the educational procedures of the lait few decades. teach introductorv chemistrv as mvtholow. .,. I3y intermingling art~clcsthat contrihute to the teachmg of chcm~stw+IS rnvthdwv w ~ t hthose wh~chcontr~hutcto the teaching of c6emist& a s a science, the editor undermines t h e position t h a t h e adopts i n so manv of his editorials. The two types of article: could, a t leas6 be distinguished by appropriate labels or by placement in special .. . sections. The Journal is impeding the-progress now being made in bringingintroductory chemistry into the realm of science if it misleads some of its readers into adopting the values and procedures of mythological chemistry.
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Literature Cited
Gordon M. Barrow Roya Roaos M I rary Co ege V ctor a BC.Canaoa VOS BO
