provoccrtive opinion Meeting One Challenge for the '90's Jack E. Fernandez and Jay H. Worrell University of South Florida, Tampa, FL 33620
. ~ ~ ~ .
We nronose that a three-semester seouence in eeneral chemistry can be designed to build chemical knowle&e and skills in such a way as ~o satisfy the needs of both nonscience liberal arts students and pre-professional science majors. The basic premise is that it is unnecessary to distinguish among students with different career goals and, in fact, toso distinguish may be a disservice to all students. Many will argue that these different constituencies require different instrurtion: Majors need the basic principles and drill necessary to be able to use these principles, whereas nonsrience majors need only an exposure to the major ideasand rurrent issues in chemistrv. We will areue that both uerouns need the . same chemistry-principles, drill necessary to understand them. and an annreciation of the real nature of chemistrv as .. a vibrant, evolving science rather than as an archive of dusty documents and techniques for solving textbook problems. Very often the chemistry in textbooks and in classrooms hears little similarity to the chemistry of the research laboratory. Textbooks ofscience are usually more rational than science itself. There are, in fact, two sciences; that of the research laboratory and that of the textbook. For example, to learn chemistry, the student must study its laws, concepts, and theories. T o facilitate this learning process, texthooks present the science of chemistry in as clear and simple a fashion as ~ossible.Nearlv all the wrone turns and defunct theories are beleted in the Aterests of cl&ty, economy, and rationality. Research, on the other hand, proceeds differently. I t proceeds hy a combination of deduction and induction, intuition, and personal bias. There are nearly as many scientific methods as there are scientists. A particular research problem given to two scientists would undoubtedly be solved in different ways. Moreover, the approach to research often reflects less scientific attitude and more personal bias. For these reasons, scientific research is a creative activity requiring imagination as well as factual knowledge. Consequently, thedifference between textbook and research scienreis that the texthook student emerges with a technical but mundane view. Helshe misses the real science-that which chanees continually, often irrationally, in a seemingly endless stream of events. The truth of this dichotomy is obvious in the difference in attitude toward science between scientists and nonscientists. The scientist lives engrossed to distrartion in his work; the nonscientist all toooften emerges from a course in chemistrv with the notion that the suhiect is drv and lrwinr. Can theie two people have studied the same slbject? We can brine about a nartial mereer of these two chemistriesby modif;ing our a'ttitudes ab&t our subject. For example, we teach equation balancing and gas laws with the admonition that these topics are absolutely necessary in order to understand what will follow. This requires an act of faith by the student; it requires that the student take hisiher medicine now so that later work will be easier. We maintain
-
-
-
that there are better reasons for studvine . ..such t o ~ i c sJohn Dalton based his atomic theory on stoichiometric ohservations!The maior iustificationfor believing in theexistence of molecules deiivld originally from kineti; molecular theory! These are important ideas, not merelv because thev allow us t o solve probiems, but also because they led to the development of our chemical paradi~m. These examples suggest that thorough understanding of ideas and their evolution is important for an understandina of the science of chemistry as-opposed to the technique or archive of chemistry. Moreover, taught in this way, there seems to be no reason to senarate students accordine to their major plans. How chemical principles developed is a t the heart of chemistw and should be offered to all students. for i t is a guide t o h o k chemistry is done today. T o more practical matters: If we teach chemistry as the science it is, we will prepare all our science majors better and perhaps encouraae some to pursue chemistry as a career. We b a y d s o attract students who might otherwise never encounter real chemistry, or a t best, who might be exposed t o a watered-down version. Additionally, anonscience major who takes a course specially designed for nonscience majors will have wasted time if s h e h e decides to pursue further study in chemistry and must begin anew with general chemi s t ~A. o r o ~ e r l vdesiened three-course seouence can solve thisproblem. " The aeneral chemistw course advocated here will encourage interested studentsto continue in chemistry for as long as hisher interests last. T o attract nonscience majors into this first course, we will have to make it exciting, stimulating, and rigorous. In order to infuse this course with material that relates chemistry to historical, social, and technology developments, we will have to use our best professors, carefully selected for their ability to inspire as well as communicate. This will improve the quality of instruction for our majors as well. The first term should employ extensive use of lecture demonstrations if a laboratory is not practical. A wellequipped and staffed demonstration facility is an absolute requirement. HOW does one place each student in the proper course of the sequence? There is a tendenry for students to seek the easiestpath and try to begin their studies with the most basic entry-level course. A carefully prepared and evaluated nlacement examination is essential. Using Zumdahl's Chemistry, 2nd ed., as a typical example, we sueeest the followine outline of how such a course can he sequenced. We also ae'knowledge that other current texts also have topical selections suitable for such a course. CHM I, 3 credit hours, no laboratory. We envision this course to be the basis for satisfying a liberal arts requirement, providing students without any prior chemistry with a basic understanding of both the necessary chemical con-
-
Volume 68 Number 7 July 1991
551
cepts and general chemical information that relates to the world around them. Instead of scanning the first three chapters of the text in five or six lectures as-we do now, we wouid slow the Dace and focus our attention on developing a firm understanding of these basic concepts. We wouG make the time for problem solving and quizzes and place a heavy emphasis on in-class demonstrations. Chapters 21, 22, and 24 are very descriptive in nature and do not require a detailed hard-core understanding of physical chemistry or bonding theory to be appreciated. This course is designed to huild student confidence and abilitv in chemistrv. If it is successfully completed we could expect to see better prepared students entering CHM 11. A chapter-by-chapter topic listing follows. Keep in mind that the latter topics for CHM I are variable and could be replaced easily by others as long as they provided a general overview of cbemistry in society, the environment, or everyday life. We do not want to lose sight of the Liberal Arts requirement for students taking the course. CHM 1 ( 3 Credlt Hours, No Laboratory) Chapter 1, Chemical Foundations The Scientific Method Units of Measurement Uncertaintv in Measurements ~i~nifican
