The Goals of General ChemistryA SYMPOSIUM
Integrating Descriptive Chemistry into the High School Program Evelyn R. Bank Westminster High School. Westminster, CO 80030 Chemistry students, whether they are taught in high school or as freshmen in collene, are usually a very diverse aroup. For this reason it is important that theteacher's expec&iois for each student be dependent upon that student's ultimate goals. Consequently, a t Westminster High School we have one set of minimum accomplishments we expect of all students. In addition, for those who are planning to go on in science we have additional more demanding goals in the theoretical and quantitative aspects of chemistry. These sets of goals are given in Tables 1and 2. Quarks and Their Properties We believe that it is important to design a course so that after a number of years have passed, the students will still retain the desired outcomes. We realize that none of the students for which high school chemistry is a terminal course will remember the details for long, but hopefully they will appreciate the broad scope of chemistry and understand its potential for solving problems as well as its limitations. I am reminded of an experience I had a few years ago a t a national meetine of the AAAS in Denver. I attended a verv interesting lecture on quarks and their properties including color and flavor. I even took notes and I thoueht I would surelv he ahle to reconstruct the whole picture aswithad been presented. I t was some time later, however, before I looked at the notes, and then I could not make sense out of them. Does that mean that I did not learn anything from the lecture? Certainly not! I t opened up a whole new vista for me. I am now aware that there is an elenant mathematical theorv which can explain the propertie~'"f nuclear particles and their interactions. I know where to begin to look if I want information,and when I read ahout quarks I havesome appreciation ofwhnt iiguing on. This is the kind of thing we hope our students will carry awa) with them from their course in chemistry. After Ihad convinced mvself of the validitv of the remise that we should teach students for what wi hope they will ultimately remember, I no longer felt it important for instance, that all students he ahle to balance equations or work stoichiometry prohlems. It was enough that they all know there is a Law of Conservation of Matter which makes this possible. Only those students who plan to go on in science need to he ahle to balance equations, work problems, and understand the theoretical concepts in greater depth. They are usually the very same students who learn the material as soon as it is presented. For this reason we felt justified in speeding up the pace of the theoretical and quantitative aspects of the course so that much more time is available for descriptivechemistry. This is essentially what we have been doing a t Westminster High School for the past twenty years. Fully one third of our school year is devoted to descriptive chemistry, most of it after students have studied the hasic theoretical concepts. Presented at the Symposium on the Goals of General Chemistry, at the 179th National Meeting of the American Chemical Society in Houston. Texas. March 25. 1980. Dr Bank was the 1980 reaplent of the James Bryant Conant Award for the leachmg of H ~ g nSchoo Cnemnstry 726
Journal of Chemical Education
Table 1. Goals for All Students The Students shall have an understanding of the Conservation laws and how Mey apply to chemical
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rsaclions. an appreciation of the historical development of our knowledge of atomic
slwCtwe and the periodic table. how atomic structure and Me periodic table relate to chemical reactivity and banding. a basic understanding of Me kinetic molecular theory and the ideal gas iaws. an appreciation of elememary thermodynamics.equilibrium, chemical kinetics. electrochemistry, and oxidation-reduction. Some understandim of how substances behave in solution. includino colllgatlve propenles. on zatlan, d l r ~ aton, C and aclds and oases Some knowledge of aescr ptwe lnorganlc organic. and nbc ear cnemoslry a basic idea of how scientists work and the potential of chemistry in Soking today's problems. the ability to carry out quantitative laboratory experiments involving the use of such measuring devices as the balance, buret, pipet, graduated cvlinder. thermometer.barometer. etc. the ability to make descriptive observations in Me labwatary and to draw conclusions from these observations. The ability to perform tests to identify selected cations and anions. an appreciation of
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Table 2.
Additional Goals for SciencerOrientedStudents
The Shrdents shall have + a greater depln of .nderstanamg of atomc svdcture, me per odlc laole. and cnemocal oandmg mcldmg nyor dlzaloon of oanar ana shapes of
molecules and ions. the ability to balance equations including oxidatian-reduction equations. and work problems based an stoichiometv and the ideal gas laws. a basic understanding of elementary lhwrmcdynamics,electrochemistry. e~uilibrium.and kinetics. t h e ability to solve problems based on simple thermodynamics. the colligative properties of Substances in solution,and molarity, and
Advantages We have found a number of distinct advantages to this approach. First of all, the students who do not quite understand a concept the f m t time they hear about it, will have a numher of other opportunities to learn it as we go through the course. For instance, we study about the development of the periodic table very early in the course. Later we show the relationship of the periodic table to our modern view of atomic structure. Then when we study electron dot formulas and the shapes of molecules and ions we refer to i t again. All through the descriptive portion of the course, the properties of the elements and their compounds are again related to the periodic table. This constant reinforcement oromotes better learning and leads to greater retention than would he the case if onlv the theoretical or onlv the descriotive chemistrv were
Another example comes to mind. The Boltzmann distribution, which incidentally, is often not even mentioned in many high school courses, is first shown in connection with the study of gases. I t comes up again when we discuss the cooling effect of the evaporation of liquids. Then it is mentioned still again in discussing the effect of a rise in temperature on the rate of a chemical reaction in the chapter on chemical kinetics. By then most of our students have a very good idea of what the distribution curve of kinetic energies really means. A second advantaee is that all students are eiven a broad background in the ;hole scope of chemistry. This is not the case in many schools. A course which deals only in the theory and the quantitative aspects of chemistry is not going to result in the desired outcomes, whether students ao on in science or not. Those who go on may know the theory and how to do problems quite well, hut when will thev ever eet a chance to yearn the descriptive chemistry which i s so relevant to their everyday lives? For those students who do not goon, this type of course is of an even greater disadvantage. The portions of the course thev learned well will he easilv. forgotten. Equally .. had is a course hated on descriptive rhernistry which ienvri out 3 lot of the theurv. Only by having a gwd apr~reciat~un of the theory, including the his
