Chemistry Basic Learning Objectives John P. Rouse Texas A&M University, College Station. TX 77843 When discussing the interface between secondary school chemistry and college chemistry, one suhject never fails to surface. That subject is the preparation or lack of preparation of the students as thev enter colleae chemistrv. Freshman chemistry sections are composed of an array of students with backgrounds in chemistry ranging from no previous chemistry to two years of high school chemistry. The upper end of this spectrum can he accommodated through the use of achievement and advanced placement tests a t the college level. The middle and lower ends of the range cause educators the most concern. The science backgrounds of these students tend to he quite varied. While some students may have come from high school chemistrv classes in which oreoaration for college . . " was stressed, others may have had only minimal exposure to manv of the maior chemical conceots. One reason for this difference is that there are no standards by which a teacher can develop a chemistry course. In an attempt to get a consensus on what "ought to be taught" a t the secondary school level, the author designed and circulated a questionnaire made up of a list of possible ohjectives for a high school chemistry course. The results of those questionnaires and the conclusions drawn from them are the subject of this paper. Basic Objective The purpose of this study was to try to establish a set of ohiectives that would encomoass those ideas or conceots of chkmistry which should he required of every studendcompleting a secondary level chemistry course. These ohjectives are to serve as the minimum foundation for a chemistry course not the entire makeup of the course. Since for a number of students this course will he their last chemistry course, it is necessary to discuss areas of chemistry which will lead toward chemical survival in a technological society. This same course must also provide for the student who intends to continue his or her studies a t a college or junior college level. Ideally, one might think it best to have two separate courses for this purpose. William R. Cary reports that having two courses works
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Journal of Chemical Education
well in a high w h d with an cmroliment d2.1H10 1 1 1. Car) and his w l l w ~ u nr e ~3Iadis11n 'Memorial llirh Srhwrl rench one course following the CHEM Study approach and a second course followinr a modified IAC auproach. This would seem to he a sound solution for a large high school, hut smaller schools often cannot afford the luxury of two separate programs. While not all school districts can support separate courses for science-oriented and non-science-oriented students, many of the concepts can he blended together in a manner to satisfy both groups. A set of "basic" objectives should. therefore. include those concents necessarv for an understanding of the benefits and failings of chemistj. They must also include those conceots and techniaues which are essential for success in any further levels of study of science. Establishment of Objectives A questionnaire was designed and mailed to teachers a t both the secondary and tertiary levels of chemical education. About 300 questionnaires were distributed. Of the 300 about 150 were returned. The averagenumber of years of high school experience of those responding was 14 years, and the average number of years of college level experience was 10. The questionnaire was designed to allow the participant to choose which of the objectives listed should or should not be included as a "basic" objective for a high school chemistry course. (For a complete list of the objectives, see Tahle 1.) After "agreeing" or "disagreeing" with each choice, the teacher was asked to rank each item as to whether it is important or not as a chemical concept. This was used as a cross check to validate certain responses. As a whole the results were fairly predictable. Tahle 1shows the percentage of those agreeing or dis-
Presented in the Symposium on the Goals of General Chemistry at the 179th National Meeting of the American Chemical Society in Houston, Texas, March 25, 1980.
Table 1.
Chemistrv Basic Learnina Obiectives % AGREE
% AGREE
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1) The student wiil.be able to demonstrate an understanding of basic measurement techniques. These techniques should include: a) Volume measurement using a graduated cylinder b) mass measurement using a triple beam balance C ) length measurements using a metric ruler 21 The student wlil be able to demonstrate the abilitv to record laboratory measurements utilizing metric units of measure. 3) The student wiil be able to convert from one metric unit to another. 4) The student wiil be able to identify the following basic laboratory equipment and demonstrate its proper uses: a) beaker b) Volumetric flask c) Erlenmeyer flask d) bunsen burner ej buret f) funnel g) thermometer 5) The student will be able to demonstrate andlor explain the proper use of safety equipment or procedures: a) eye protection b) fire extinguisher C ) handling of chemicals 6) The student will be able to explain the steps of the scientific method. 7) The student will be able to state the Law of Conservation of Matter and Energy. 8) The student will be able to perform calculation related to the following: a) density b) formula mass C) moles d) percent composition e) stoichiometric problems f) enthalpy g) gas laws h) molecular weight i) molatity 9) The student will be able to use significant digits in recording measurements. 10) The student will be able to perform calculations using scientific notation. 11) The student will be able to differentiate between elements. compounds, and mixtures. 12) The student will be able to differentiate between physical changes and chemical changes by listing examples of each. 13) The student will be able to list the symbols of the following Common elements: hydrogen. carbon, nitrogen, oxygen. sulfur, sodium. aluminum. lead. phosphorous, chlorine, iron. zinc, copper, bromine, silver, tin, iodine, barium, and mercury.
14) The student wili be abie to write simple chemical formulas. 15) The student will be able to write and balance simple chemical equations. 16) The student will be able to correctly define the following terms: a) exothermic b) endothermic C ) mole d) atomic number e) isotope f) electron 9) proton h) neutron i) period j) family k) ionic compound I) electron affinity m) electronegativity n) ion 0 ) isomer p) covalent bond q) kinetic energy r ) melting point 5 ) boiling point t) A ~ o g e d r onumber '~ U) entropy v) equilibrium W) calorie 17) The student will be able to determine empirical formula from the percentage composition data. 18) The student wili be able to find the molecular formula given the molecular weight and the empirical formula. 19) The student will be able to draw the Lewis dot structure for any atom. 20) The student will be able to list and describe the properties of each of the states of matter. 21) The student will be able to define acid and base using the following: a) Bronsted and Lowry b) Arrhenius C) Lewis 22) The student will be able to name common compounds given their formulas such as: hydrochloric acid, sulfuric acid. Sodium hydroxide, water, and carbon dioxide. 23) The ~tudentwill be able to list the diatomic molecules. 24) The student will be abie to use the pH scale to distinguish between acid and base.
100 100
99 99 100 100 97 99 99 99 98 99 99 81 89 88 88 97 98 99 too 97 81 97 95 90 92 88 95
93 90 74 99
94 96
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agreeing on any particular item. On the following items, 10%
culttask, hut one must keep in mind that thfs set of ohjectives is to serve as a minimum foundation upon which a comprehensive program can he built. Some of the comments received suaeested that a number of these ohiectives should he covered i n a n earlier course such as physical science. The author felt that these should be included to assure that they are met a t some point. Several comments were received which listed other possible topics to he included. For a partial list of these sugg&tions, see Tahle 2. Those areas which were commented on most often were nuclear chemistry, electrochemistry, organic chemistry, and descriptive chemistry. It is the author's opinion that most of the tonics listed in Tahle 2 eo - hevond . the minimum requirements for high school chemistry. This is not to say that they should not he included hut rather that their use should
Table 2.
Suggested Areas Which Were Omitted o n Questionnaire
Nuclear Chemistry Biochemistry Electrochemistry Organic Chemistry Descriotive Chemistw Oxidation-Reduction Equilibrium Periodicity ~
~.
Atomic Theory Energy Topics Problem Solving application^ Kinetics Molecular Geometry Quantum Mechanics Atomlc Structures ~
~
not result in the exclusion of other essential concepts. It is the author's primary concern that every student completing a high school chemistry course he able to accomplish certain "basic" ohjectives. Unfortunately, as the results of this questionnaire show, it is difficult to reach a consensus among chemistry teachers as to which ohjectives should or should not be considered minimal. The results did show that there seem to he two different schools of thought about this idea. One group considers all those objectives shown important enough to he Volume 58
Number 9
September 1981
715
included as "basic" requirements for high school chemistry. This is the lareest of the two erouos resoondine. and it includes nearly ail of the tertiar;level teachers t h a t answered the auestionnaire. T h e smaller erouv, . . about 15 Dercent of I h ondary school chem&tryteacher is one of building student's interest in chemistry rather than strictly doing college preparatory work. One must bring together "real world" ideas with the more abstract concepts in a manner which is understandable and interesting to a majority of the students enrolled in chemistry. A set of modules is currently on t h e ~ o r o a c ht o the market which utilize a n interdisciolinarv" a .. teaching of chemistry (2). ~ i l l i a m ~ a r yarticle 's on the use of a modified IAC approach program shows a marked increase in the enrollment of the chemistry classes which might he interpreted as an increase in the number of "general" student enrolling ( I ) . Some of the teachers responding implied t h a t designing a course for "general" students usually results in the use of more "watered down" concepts. As Douglas Halsted points out in his December 1979 paper in this JOURNAL many high school teachers have a fear of "watering down" their chemistry courses so the course will be understandahle to a eeneral student audience (31. I t is the author's ooinion t h a t %hisdoes not need to he the case. If the teacher properly stresses vrohlem-solvine techniaues, then the student should the key approach to learning. In a gaper presented a t the Pennsylvania Association of College Chemistry Teachers meeting in April 1979, Gilbert stated ( 4 ) , It is my conviction that the types of problem solvingskills we develop and encourage in our students will become long term and valuable patterns for them throughout their lives.
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Althoueh orohlem solvine" is definitelv a techniaue which A
all students should he very familiar with, Gilhert points out a serious difficultv which is likelv t o interfere with the orohlem-solving process and t h a t is the lack of understanding of the conceDts needed to solve the orohlem. Therefore, if one expects ail chemistry students tb understand and use the oroblem-solvine ao~roach.then he must first teach some basic conce& can he taught in a manner that is both interesting and understandahle. Chemistry teachers must also keep in mind the entry level of their students with regard to their mathematics and reading skills. Increasing the students' frustration levels by requiring them to read text material that is beyond their reading level or by expecting them to use math techniques that they have not become familiar with will greatly decrease the chances for learning. Concluding Remarks Before designing a curriculum for any course, one should carefully assess the needs of the students. T h e course should be developed in such a manner as to meet as many of those needs as possible, however, the ohjectives should also reflect the types of students involved in the program. Special care should he taken so t h a t the minimum required ohjectives should be realistically achievable by all of the students enoeoole rolled. Our societvneeds . . who are aware of both of the benefits and shortcomings of science and technology; therefore, a special effort should he made t o include ohjectives which will cause the students to think about these concerns. Chemistrvmust remain relevant. What eood is it if the student knows the Lewis dot structure of a compound if he cannot realize that our energy sources are not inexhaustible?
716
Journal of Chemical Education
A list of suggested hasic learning ohjectives for a high school chemistry course has been compiled from the results of the questionnaires. These learning ohjectives are written in a shortened form. The author suggests that for classroom use they be put in the form developed hy Mager (Fi). The suggested basic learning objectives are as follows. The student will he able to
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demonstrate an understanding of basic measurement techniques demonstrate the ability to record lahoratory measurements utilizing metric units of measure
equipment explain the meaning of the Law of Conservation of Matter and Energy demonstrate prohlem-solving techniques necessary to solve prohlems relating to topics such as density, formula mass, percent composition, stoichiometry, gas laws, rnolarity, empirical formula, and molecular formula use significant figures and scientific notation when recording measurements and performing calculations list the correct symbol and name for common elements (including groups IA-VIIA and commonly used transition elements) utilize the periodic table to locate elements and predict their properties, atomic number, oxidation number, and atomic mass write correctly the chemical formulas of commonly encountered compounds and state their most commonly used names write and balance simple chemical equations define terms such as exothermic, endothermic, male, atomic number, isotope, electron, proton, neutron, period, family, ionic compound, ion, covalent bond, kinetic energy, melting point, boiling point, equilibrium, and calorie list and describe the properties of each of the states of matter define acid and base according to the Bronsted and Lowry theory use a pH scale to distinguish between an acid and a base state the general chemical composition of household chemicals such as detergents, poisons, and common medicines identify and give a common example of each of the basic types of organic compounds including esters, alcohols, ethers, aldehydes, ketones, acids, amines, and hydrocarbons list and explain the assets and liabilities of the different energy source options discuss the good and bad effects of the use of chemicals (i.e., medicines, cosmetics, food additives, pesticides)
. . . .
to reflect the minimum reqii;edbhjectives, not hll the ohjectives for a chemistry course. Some areas have been excluded h r ( . a ~ 1l1e ~ e amhs,r 1~01. that d ~ j r t . t i r vIiI I t h i area.; ~ sh
