through equilibrium concepts; thermodynamics, voltaic cells, and nuclear chemistry a t the higher levels. The package complements courses designed for both science and non-science majors a t either two- or four-year institutions. Documentation and Ease of Use The documentation provided within each program of the package is clear, accurate, and self-explanatory. Although special instructions are not needed for the instructor, a general descriptive sheet containing a full table of contents is advisable. No worksheets, soecial eouioment. or other materials are nrrdrd hy the student. Studrntp nepd nu rumputer knwledgr; they merely check out a particular disk and without any, ur little instruction, can begin working problems in microchem. A menu is provided a t the heginning of each disk so that a student may go directly to a desired area of interest. The oroeram does not nerform mathe" mntieal manioulstions: therefore. students muat demmstratr simple arirhmetirvkilla o r use raluulators in murh the same way they demonstrate these skills during a test. Input is straightforward with proper prompts, hut there is no margin for input errors. Significant figures must be adhered t o and if letters are entered where numerical values are expected, the answer is considered wrong. Prompts are very good and each program permits the user toskip sections. There seems to be no input that interrupts the program or leaves the user stranded. Subject Matter Content "Microchem" coven the basic concepts of general chemistry, not with descriptive explanations but with supplemental prohlemsolving materials. Students are allowed to review and test their comnrehension a t their own pare. The program? vary in difficulty uithin each xul,jrrt-matter area. which permits the student 10 work thruugh the 50 interactive programs progressively t o more difficult programs within each topic before advancing. Drill and practice reinforce and enhance the student's understanding and mssterv of a oarticular skill with ouestions. whk.h are iollwvrd by immedme r v a l u a t i r ~ respunses. There iz huilt-~nrcmrdial msistanre in wme of the programs, provided as needed. The program gives the answer by working the prohlem in basic steps; this is then followed by a similar problem. "Microchem" cannot be modifieh; i t has a write protect feature. Pedagogic Value Most of the 50 programs in "microchem" are designed t o recognize students' weak spots and concentrate on correcting them. If a question is missed in a drill, the program makes sure that the student is asked that type of question again before ending the section. Questions are presented in a logical pedagogical order so that proceeding to the next question may be prevented until a question of that type is correctly solved. When a wrong answer is given, the program gently corrects the student; when the student enters a correct answer, there is an encouraging display, "That's fine" or "You are carrect" and the program continues on t o the next prohlem. Since most of the programs are designed to be challenging, their use builds students' confidence or indicates areas that need additional studv. This comouterized method of prohlem solving to learn the fundamentals allows the instructor more time to
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present difficult concepts to students on a one-to-one basis. Student Reaction "Microchem" was tested by students a t various levels. Non-science majors found the first disk (I) containing programs 1-17 most helpful, especially the first seven programs that deal with the most elementary concepts: however, they were not motivated to continue. Science majors, especially chemistry majors, were motivated to continue to use disks I1 and 111. The more advanced students, although they examined the entire package, were enthusiastic with only the higher level subjects found in disks 111and parts of disk 11. In general, the responses were favorable and the 6 packages that were available for student use were used consistently. Summary "Microchem" is an excellent interactive, user-friendly tutorial program that can he used to teach both fundamental and advanced concepts in chemistry. Although it is excellent in teaching concepts through problem solving, it fails to explain the fundamentals descriptively. This must be left up to the instructor. Even though its topics parallel those in Petrucci's "General Chemistry," the "microchem" package can be used as a supplement to any general chemistry course. If an instructor wishes to use the "microchem"software package, but not the text, i t would be useful t o include a small manual presenting basic explanations of the concepts covered in each program. In summary, the "microchem" package is a good tutorial program for any general chemistry course, especially where prohlem solving is emphasized. Donald Foster Mullica and J a m e s L. McAtee, Jr. Baylor University Waco, TX 76798
more purge than passlng." This book makes pleasant reading hecause of the author's style and his persistence in "walking through" the logical development of an ideaor calculation. The math is understandable t o a high school student; there are no integral signs that I recall in the text. The audiences which could gain from reading this book include all chemistry teachers, especially those dealing with novice students or students fulfilling a "liberal arts" requirement, students at any level looking for challenging, independent presentation of chemical concepts, and theoreticians Looking for data and relationships exhibiting both "regularity" and "deviation" which need further exploration. George D. Sturgeon University of Nebraska Lincoln. NE 68588
Polar Covalence R. T. Sandenon. Academic Press, Inc.. New York, NY, 1983. xii 240 pp. Figs. and tables. 16 X 23.5 cm. $19.50.
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Incalling the author a teacher, I intend to say more than that he has been hired to t a c h in an educational institutim. His personality, his oreiudices. and all his oassion for helnine , . .. students tu understand are e x p o i ~ d!'rankly in 1hi.i mmt rereof crposition of his &as about chemical prorrssrs and huw they 'an he understood and explained most successfully. Sanderson's approach in "Polar Covalence" upholds the concepts of the polar covalent bond. eleetroneeativitv (to four sign~filantfigurer!), and partial charge. He hns hpen nt,lr u, ralrulate buud cnergirs and renctionmthslpieiquite well in hundrrdsof cases spanning organic and inorganic species. While claiming coalescing theoretical support, he is openly empirical about rationalizing adjustments or special provisions as ne-ary: he acknowledges puzzling cases yet to be fit into his system. Striking phrases and assertions abound. For example: "Insistence on 'rigor' a t the mpense of understanding has always seemed !o me foolish and unnecessary.", "studies iesigned to make chemistry simple enough 30 I myself could understand it.", and "stuients whose completion of high school was
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Volume 61
Number 12
December 1984
A327
