AN INTRODUCTORY, COMBINED COURSE IN CHEMISTRY AND PHYSICS EDWARD C. FULLER Bard College, Annandale-on-Hudson, New York
FOR SOME time it has been evident that the undergraduate preparation of students for chreers in chemistry is becoming progressively more complex. Fundamental chemical research is developing so many new facts and theories that chemistry teachers are bedeviled on the one hand by the problem of expanding the content of their courses and on the other by the demands of their fellow educators that chemistry students of today must have much more general education in order to live as intelligent citizens in our contemporary society. Three approaches for solving this problem are open to us: (I) we may drop some of the older subject matter in our chemistry courses to make way for newer-more integrative-knowledge; (2) we may expand our chemistry courses at the expense of general education; (3) we may extend the time dwoted to undergraduate training. At Bard we haw chosen the first approach, with the emphasis on the integration of knowledge. Since the fundamental theories of chemical reaction are being elucidated more and more in terms of physical (mechanical and electrical) concepts, we have tried to make such concepts the foundation of our approach to chemistry. The integrative concept upon which the first se mester's work is based is the atomic-molecular theory of matter. This approach requires a working knowledge of simple kinematics and dynamics. Laboratory observations of the velocities of moving bodies a t known times are correlated by graphing the data on Cartesian coordinates. The straight line relatiionship found is analyzed algebraically to bring out the underlying unity of algebra and geometry as two tools for studying quantitative data. The basic concepts of force and mass are developed by similar techniques. Newton's laws of motion serve to correlate these concepts. The equal arm balance is studied and used to determine densities by Archimedes' principle. Hydrostatics and the concept of pressure (with particular application to the barometer) are included here. A laboratory development of the basic laws of mass relations in chemical reaction (conservation of mass, definite proportions, multiple proportions) leads naturally .irlto the atomic concept of matter. Atomic masses, equivalent masses, and valences are studied with the introduction of symbols, formulas, and chemical equations to facilitate the presentation and discussion of chemical facts and calculations. At this uoint., exoonential notation and loaa. '
Presented before the Division of Chemical Education a t the 111th mcetine of the ~~~~i~~~ chemical societv in *tlantic ~ity~~~il1~18.1947.
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rithms are studied briefly to make calculations less arduous. A study of the expa&on of bodies with increases in temperature is used to develop the empirical concepts of thermometry. The cubical expansion of a liquid is studied in the laboratory, again using both the graphical and algebraic methods for analyzing data. Mechanical work and energy, both potential and kinetic, and the law of conservation of energy are studied next. A study of the behavior of gwes under differenttemperatures and pressures (again using graphical and algebraic methods for analyzing laboratory data) is used to develop the absolute scale of temperatures as well as Dalton's law of partial pressures, Graham's law for gaseous diffusion, and Gay-Lussac's law of combining volumes. The kinetic-molecular hypothesis is then introduced and the kinetic theory developed to synthesize the above phenomena. The concepts of molecular masses and velocities, the gram-molecular volume, the general equation of state for gases, and Avogadro's number are included here. The kinetic-molecular theory is then applied to changes of state along wit,h measurements of specjfic heats, latent heats, and the mechanical equivalent of heat in the laboratory. The concepts so far developed in the course are now used to facilitate understanding the.chemical reactions of oxygen; hydrogen, and water. The colligative properties of nonionic solutions are next studied and interpreted in terms of the basic ideis of the atomic-molecular theory. The integrative concept underlying the second semester's work is the electron-proton-neutron-quantum concept of atomic structure. The course begins with a study of electrostatics, electrolysis, and cathode rays to establish the atomic nature of electricity and the electron's ability to exist independently of other matter. Vector addition is introduced to facilitate the study of electrostatics. Next a study of radioactivity establishes the fact of atomic substructure and leads to the necessity of accepting a nuclear atomi A study of the transfer of energy by wave motion and the laws of ra-&ant energy (including kinds of spectra and spectral series for hydrogen) introduces the student to elemeutary quantum theory, the Bohr atom, and the periodic table of the elements. The Einstein equation for the equivalence of mass and energy is illustrated by considering reactions. The sienificance of .....- various nnclear ~ ~ ~ isotopes and atomic numbers emerges and the relationship between atomio structure and chemical reactivity is emphasized.
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A study of d.-c. electricity is now undertaken to es- cepts employed to interpret these facts (which are tratablish an understanding of the meaning of and relation- ditionally taught both in elementary chemistry and in ship between current, electromotive force, resistance. elementary physics from somewhat different viewpoints Some circuit theory and bridge measurements are in- and with different techniques) are taught once with the cluded. The principles of conductance in solids are two approaches combined; (2) the integration of chemextended to conductance in solutions, leading to a study istry and physics (which has been so fruitful in research) of ionization. The study of ionic equilibrium is ex- is brought out more clearly in the one course than is tended to a consideration of chemical equilibrium in customary when two separate courses are given; (3) general with an investigation of specific reaction rates mathematical tools for analyzing data are sharpened by in relation to equilibrium constants. constant application to many different problems in The first half of the third semester of the sequence is physical science. The disadvantages of the sequence devoted to a systematic study of the important families are: (1) the emphasis during the first two semesters is of the chemical elements. Elementary qualitative rather heavy on the theoretical aspects of physical analysis is used in the second half of the semester to science with only enough facts brought in to formulate round out this study. The fourth semester of the s e the fundamental hypotheses and laws studied; (2) some quence is devoted to the study of furtherphysical prop- of the subject matter ordinarily covered during the first erties of matter, including surface phenomena, elastic year of college chemistry is postponed until the fall moduli, hydrodynamics, rotary and simple harmonic term of the sophomore year. motions, acoustics, geometrical optics, magnetism, and The author wishes to acknowledge the important cona.-c. electricity. tributions of Dr. Paul H. Garrett, Professor of Physics, The advantages of the sequence described above are: and Dr. C. Theodore Sottery, Professor of Chemistry, (1) certain factual information and the theoretical con- to the development of the course described here.
