The Australian Academy of Science School Chemistry Project A New-Generation Secondary School Chemistry Course R. B. Bucat and A. R. H. Cole University of Western Australia, Nedlands, Western Australia, 6009, Australia In a strongly worded editorial in this Journal,' Lagowski has lamented the fact that beginning students of chemistry are usually presented with an organized array of principles without any experience of the observations on which those principles have been based. The Australian Academy of Science has anticipated that situation by the development of a new-generation secondary school chemistry course during the years 1980-1984. The course materials include a two-volume textbook entitled Elements of Chemistry: Earth, Air, Fire and Water and associated teacher's guides.2The major thrust of this project has been to provide a chemistry course that is more interesting for, more enjoyable to, and more understandable by a wider spread of the school population than has hitherto been the case. At the same time, where necessary, rigor is maintained to ensure that the course is suitable as a prerequisite for tertiary-level chemistry courses. The purpose of this paper is to summarize the philosophies behind the course and the consequent design decisions regarding the selection and sequence of the chemistry content. Context for Change The new course is a reaction to the previous wave of principles-based curriculum materials. Without denying some of the very good features of those courses, the following perceptions provided impetus for change: They were discipline-based rather than learner-hased and were narrowly representative of "chemists' chemistry". These courses were hased on theories, principles, and organizing themes that were both abstract and difficult. The students' first encounters were with abstract theories, which seemed to have a "turning off'effect. Too often the theories presented were based on experimental information that was unknown to the students, and so the interaction between observation and explanation was missing. The order of presentation was backwards-theories were presented first and the detailed chemistry of individual substances was found in the last chapters of the books. So, the theories were perceived by students es the "facts" of chemistry that govern what happens, rather than as provisional explanations of what happens. External examinations for university selection emphasized theoretical concepts and principles to the exclusion of reaction chemistry, lahoratory experiences, and applications. So, "uncomprehending learning of facts was largely replaced by uncomprehending learning of theorie~".~ The courses were suitable for, and attractive to, tertiary-oriented students only, at the expense of the vast bulk of secondary school students. A stated commitment to the experimental nature of chemistry was not always carried through in the classroom. Students gained little familiarity with common chemicals and their reactions. Few attempts were made to demonstrate the chemical nature of the substances that people handle every day. The influence of chemistry on society and the individual was
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ignored, so that courses lacked human, social, and industrial components. Interrelationships with other sciences were scarce. The forus wason the physicalsutrsandstrurturesofsubstances, rnther than on reactions of subrtanrrs to form other S U ~ ~ U ~ ~ C P S . Guiding Philosophies and Deslgn Declslons of the AustralIan Project The key philosophies to which the development team continually referred are summarized below. In each case, related decisions regarding the design of the course are listed. (1) A school chemistry course should be satisfying, meanineful. and useful for all students-for those who are not pro&ding to te;tiaky study a s well a s t o those who are. Theemphaais ison theinflurneeofchemiatry on ourdaily liwsnot nMy on teat-tuhe reactions in the rlnssrocm. As much as possible, the chemistry is discussed in relation to Local contexts. Theories regarded as too difficult, too abstract, or unnecessary for the explanation of observations in the course are not included. (2) The essential focus of chemistry is the change of substances into other substances. The emphasis should be on chemical reactions of substances, rather than on their physical properties. From the first p n g w the focus is an chemical renrrions rnther than on theories of a physical nature, such as atomic structure, molecular structure, prediction of molecular shapes, hybridiration, and ionization energies.
(3) Chemistry is a n experimental science, so school chemistry courses should inuolue laboratory and field experiences by the students. Experiments can he the vehicle for arousal of curiosity, familiarity with common substances and their reactions, appreciation of aesthetic aspects of the subject and active participation by the students rather than passive reception. This approach to laboratory work allows development from concrete situations to abstract ideas. Experiment, description, and theory are integrated throughout this course. Experiments and/or demonstrations are introduced in the textbook at the appropriate moment. There is no separate laboratory manual. Almost all topics are introduced via an experience in the laboratory or by reference to experience in everyday life. Where appropriate and convenient,experiments are used to pose problems and to develop patterns, concepts, and theories rather than simply to illustrate theories previously described. ~~
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Based on a paper presented at the 8th International Conferenceon Chemical Education, Tokyo, August. 1985. Lagowski. J. J. J. Chem. Educ. I985 62, 915. 2Available from The Publications Officer, Australian Academy of Science. G. P. 0.Box 783. Canberra. A.C.T.. 2601. Australia. Price ~ $ 2 1 . 9 per 5 volume, ~eacher's~uides~ $ 7 . 9 5each. Gillespie, R. J. Chem. Canada 1976 28,23.
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Volume 65
Number 9
September 1988
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Table ol Contents Volume 1 Part 1. Earlh I A . Metals "Let's statwith copper" Our dependence on metals The properties of metals The structure of materials: bondlng Oxidation-reduction reactions: electron transfer Elemachemical cells: electricity from chemical change Electrolysis: chemical change caused by electricity Chemical stability: which reactions occur? Corrosion of metals Reacting quantities Mineral resources Metal extraction and pvificatlon A summary of the chemisby of soma imporlam metals
16. Non-Melals 1.14 Carbon and its comoounds 1.15 Silicon and Its compounds 1.15 Phosphorus and its compounds 1.17 Sulfur and its compounds 1.18 The halogens and their compounds 1C. Classlflcallon o( tk%Elements 1.19 me pwlodic table: arrangemems of electrons in atoms Parl2. Atmosphere Our dependenca on the atmosphere 2.1 The gases of the atmosphere 2.2 2.3 What are gases? The three states of matter 2.4 Experiences with gases: quantitative relationships 2.5 The atmosphere as an industrial resource 2.5 Air pollution
Pad 3. Energy 3.1 Our dependence on energy 3.2 Sources and forms of energy 3.3 Fossil fuels as energy sources 3.4 Alternatives to fossil fuels 3.5 Foods as fuels: carbohydrates 3.5 Energy transfer during chemical reactions Rates of reactions: how fast do reactlons go? 3.7 3.8 Energy in indushy
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The experiments are written in a manner that encourages an enquiring approach.
(4) Theories, concepts, a n d generalizations a r e import a n t for the organization of knowledge, but only provided that:
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(a) t h e s t u d e n t s a r e familiar with the knowledge being ordered. T h a t is, students should experience "what happens" before facing t h e question "Why does i t happen?" T h i s approach avoids a purely theoretical introduction t o chemistry a n d discourages t h e perception t h a t t h e theories a r e t h e "facts" of chemistry, which determine (rather t h a n help t o explain) chemical properties.
Refore the periodic tahle is discussed in detail. students are given opportunities to experience metal reactions, cnrtmn chrmistry, and the chemistry of sulfur, phwphorus, nitrogen, and the halogens. Only after periodic classification has been discussed in terms of the chemistry of groups of elements is an explanation in terms of atomic structure introduced. Only after metal properties have been experirncrd is an attempt made to explain the differences between the structurex of metals, ionic substances, and covalent suhstanres. A formal consideration of arid-base theory is included only after many examples of aodr and basrs and their chrmirnl reactions have been experienced.
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(h) t h e knowledge to be ordered is useful a n d significant to the srudents in their present or potenrial environments. Some traditional content has been replaced by other content judged to he more useful and more interesting. Examples of excluded concepts are standard states, standard enthalpy changes, standard reduction potentials, sophisticated models of atomic and molecular structure, hybridization, electron-pair repulsion theory to predict molecular shapes (although the consequences of molecular shapes are retained), enthalpy and entropy changes as
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Journal of Chemical Educatlon
part 4. Water 4.1 Our dependence on water 4.2 Water resources: quantity and quality The physical properties of water: intermolecular fwces 4.3 4.4 Solubility: "like dissolves like" Surfactants:soaps, detergents, and flotation agents 4.5 4.5 The composition of water: a hislwical perspective 4.7 The chemistry of water Chemical equilibrium: how far do reactions go? 4.8 4.9 Acids and bases 4.10 Types of reactions in aqueous solutlon 4.11 Chemistry In solvents otherthan water 4.12 Water treatment
factors that govern whether reactions will occur, and all hut simd e examples of systematic nomenclature of organic cbmpounds. Examples of topin included are corrosion, problems confronting development of improved batteries, properties of good fuels, the "hvdrocen economy", the chemistry of the car engine, eutrophication of waterways, water treatment, air pollution and its control, and swimmine- .no01 chemistrv. are aiven an extended . Polvmers . nlverage, uith empharis on the chemisrry ofpnrducts that ran he purchased in thr local hardware store. Organic chemistry is introduced relatiwly early since it deals wrth suhstanr~athat are familiar to most people. (c) t h e theories a n d concepts a r e not too difficult for in^- bv t h e bulk of students. m e a n i n-~,f u understand l Periodic classification is based on metallnon-metal character and formulas of compounds, rather than ionization potentials, electron affinities, and atomic radii, which are not observable by students. More difficult concepts such as equilibrium and the nature of intermolecular forces are presented late in the course. A spiral curriculum is used for several concepts. For example, students experience acids and bases on many occasions, with just sufficient explanation for the immediate purpose, before formal acid-base theory is presented. For the purpose of explaining the properties of metallic, ionic, covalent molecular, and covalent network substances, a very simple picture of atomic structure is used; electron energy Levels are not introduced until required to explain periodic classification. Organic chemistry, which is taken to a level that is relatively undemanding conceptually, is presented earlier than in most courses. Some topics for which there has heenevidence of very poor undrrstanding hy school students have heen excluded. In this category are maw of the topics iudgrd to he of limited utility (see 4b . . . above). (5) Chemistry is not a n isolated body of knowledge a n d processes, c o n f k e d to test-tube reactions i n t h e classroom. T h e interaction of people a n d chemistry is important. I n this context, chemistryis not value-free.
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The structure of the course emphasizes our dependence on earth, air, energy, and water resources, as well as on synthetic suhstances. Opportunities are provided in the course for discussion of topics such as air pollution, water pollution, limitations of energy resources and options available, benefits and costs of the minerals industries, and costs and prevention of corrosion. (6) Students should be aware that chemistry is the basis of euerything, liuing a n d non-liuing. Numerous examples and applications are presented of chemistry in the biological and earth sciences and in everyday life.
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(7) A chemistry course should prouide opportunities for students to become aware of the role of chemistry in industry and technology-especially when such industry is local to the school or home. Frequent reference is made to industrial applications of chemical principles. The principles and the industrial application are presented as one portion of the course-not as two separate pieces of information to be remembered in isolation. For example, the electrolyticproduction of sodium hydroxide and chlorine, and the electrorefiniug of copper are integral parts of the discussion of electrolysis. (8) We are a consumer society and people should haue a basic knowledge of the chemistry of foods, building materials, polymers, and other common products. The course contains frequent discussions of the chemistry of consumer products.
(9) Euery opportunity should be taken to relate the chemistry content to out-of-school contexts with which the students are familiar.
Although recognizing that chemistry is international, Australian applications are presented wherever possible, and opportunities are provided for class investigation of situations close to the school. We are discussing with publishers in other countries whether it is feasible to produce modified editions in which references to Australian applications of chemistry are replaced by examples from each of those countries.
Contents and Sequence A list of the contents, chapter by chapter, is shown in the table. T h e sequence of topics differs from most texts in that it does not commence with atomic structures. hondine. the periodic system, and molar quantities. I n line a i t h the&erall philosophy that we should move from the concrete and observable to the abstract and theoretical, we commence "Earth" with reactions of familiar materials-the common metals. This leads naturally to oxidation and reduction, electrochemical cells, electrolysis, corrosion, and reduction of ores to metals. A similar, logical path of development is followed in the other major sections.
The Product The product is attractive and highly readable.The immediate u ~ t a k eof the course throuehout Australia has been very high, and considerable interest has been shown from overseas countries. The response of users has been most encouraging and indicates that many students are actually enjoying reading about and doing chemistry.
ACS Gives More SATlSfaction The Association for Science Education has just released three more volumes of their Science and Technology in Society (SATIS)curriculum resource series. Volumes 8,9, and 10 provide up-to-date, exciting activities to help introduce students to science in the real world. The complete SATIS series of 10 student resource units plus a teacher's guide contains
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lessons in 100 different science tooics.. copyright-waived photocopy masters, hundreds of student activities, comprehensive index, teaching techniques, and a list of additional activities and resources. Among the activities suggested to involve students in each topic are simulations, data analysis, comprehension questions, discussions, and role-plays. Problem-solving and decision-making skills are stressed in all units. The index help teachers or group leaders choose activities related to a specific subject. The teacher's guide suggests extensions of activities and additional ways to make science relevant to students. The original seven-volumeset plus teacher's guide sells for $148 in the United States and includes postage. The three new volumes sell for $58, or one can order the complete package--dl 10volumes, plus teacher's guide for only $199. Postage and handline charees are added to all foreizn orders. For a complete list of topics and aetGities and sample pages write or call, Office of Precollege Science, American Chemical Society, 1155 Sixteenth St., N.W., Washington,D.C. 20036; (202) 812-4590.
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Number 9
September 1988
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