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NEW EICLAND ASSOCIATION of CHEMISTRY TEACUERS Should Physics or Chemistry Come First? J . BARTON HOAG United States Coast Guard Academy, New London, Connecticut
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ROM actual experience we who teach chemistry and phys~csare continuously confronted with the fact that these subjects have grown so stupendously in the last few years that i t is extremely difficult for the student to acquire in the first-year courses a really comprehensive knowledge of the fundamentals of these subjects. Many attempts have been made by the various schools of our country to overcome this difficulty. One of these has been the introduction of survey courses. Here, less emphasis has been placed on detail and greater on relationships between the sciences. In contrast, other schools have attempted to concentrate on selected topics. It is with this latter approach that I am in greater sympathy, a t least for the iirst courses. I believe the survey idea fits better in the senior year of the college training. The selection of topics is of necessity dictated by the administrative atmosphere of the particular school. A technical school, for example, must select and emphasize the applied phases of science; an agricultural school must attempt to illustrate the fundamental principles by applications in botanical and horticultural fields; a college for women, such as Connecticut College, must emphasize the cultural aspects of science; and the United States Coast Guard Academy must teach the fundamental laws by means of applications taken directly from this service unit. However, there is a third means by which we in physics and chemistry can cover the extensive topics of our general college courses. This consists of a closer coordination between the two departments and an elimination of the overlapping material. I wish most emphatically to avoid raising any question as to which topic belongs strictly to chemistry or to physics. For example, both physicist and chemist need a clear knowledge of the nuclear atom. I realize that in the average college where the two departments operate in separate buildings and under separate budgets and with separate staffs, the question of priority to a particular topic is sometimes of considerable importance. However, I wish to avoid such confusion. In fact, I ask
' Abstract of an address presented at the Sixth Annual Summer
Conference, New England Association of Chemistry Teachers, New London. Connecticut, August 24,1944.
you to imagine that the physics and chemistry departments have been fused into a single department and that the teaching staff is entirely free to order their material and select their topics without conflict between two departments. Such, indeed, is the fortunate situa'tion a t the Coast Guard Academy. Now we are in a position to discuss the subject of "which should come first-physics or chemistry." You will notice that the word "first" is not used in the sense of relative importance of physics or chemistry, but refers to the sequence in which these topics are to be taught. In addition to having both physics and chemistry in one department, I wish to add one further qualification before presenting my analysis. I ask you to assume that all students in your school are required to take both beginning college physics and beginning college chemistry. This is the case a t the Coast Guard Academy. Let us ask ourselves why more students take chemistry than physics in the usual liberal arts college. Here is a list of possible reasons or explanations for their choice : 1. The elementary chemistry course is less mathematical. 2. The student knows by reputation that the chemistry course starts at his previous level of training, that it is fairly hard to learn, but not too hard, and that he has a chance of passinn .the course. 3. His friends are taking the course. It's the "thing to do." 4. His parents recommend it. 5. He dreams of fame and fortune through the discovery or invention he may make after mastering the subject matter. 6. The chemists whom he has met are looked up to in the community in which he lives. 7. There are a large number of commercial and teaching jobs ahead of him. 8. A strong-minded counselor assures him that it is the best course he could possibly take. 9. He received a better training in high-school chemistry. where the teacher was better prepared in subject matter and educational matter than the physics teacher. As we all know, the football coach in a high school is sometimes called upon to teach physics.
Some of these, perhaps all, form the pattern which arouses the student's interest in chemistry and compels him to direct his efforts along this path first. Of these, I believe the most important are:
1. Thelack of the prerequisite of mathematics. 2. The economic factor-that there are more jobs available to chemists than to physicists
I believe that the future of our country will still demand many more chemists than physicists but that the physicists are due for a marked increase in the demand for their services. From the two major factors mentioned above, I conclude that in a liberal arts school, chemistry should come first because it is essentially nonmathematical. However, in a technical school such as the Coast Guard Academy where mathematics starts as soon as the students arrive, I believe that physics may well come first. I t then becomes possible to reduce the descriptive chemistry (which is so admirably taught in our high schools) and concentrate on the underlying principles and to work the problems of chemistry. If physics in the technical school precedes the chemistry course, the student will already have had a thorough drill in the solution of algebraic equations and it becomes pmsible to place the chemistry course on a much more rigorous foundation. In addition, in his physics course, the student will have learned how to manipulate instruments with his hands in the laboratory, how to increase the accuracy of his experiments, and how to discuss intellieentlv ,the errors of his measurements. Assuming, then, that we are teaching in a technical school and that chemistry is to follow the physics course, what topics previously covered in the standard physics course can now be omitted from the chemistry course, permitting either increased drill of the regular chemistry or permitting additional material to be injected into the chemistry course? I have no doubt that all of you have observed the increasing trend in chemistry toward the introduction in the general course of more and more material of the ahvsical chemistrv type. Here, then, is a means for providing room for the instruction of more fundamental principles of chemistry such as atomic structure, kinetic theory, and gas laws, or for the better mastery by the student of the more purely chemical topics. I have gone through several standard textbooks of chemistry and selected the topics which are covered more or less thoroughly in the usual physics course. These do not need to be taught in the chemistry course if a physics course is a prerequisite. I ask you to remember that I am not calling them either chemistry or physics, but merely pointing out that they constitute the overlapping topics in the two branches of science and, if presented in only one course, their omission will leave additional time for better teaching in the other course. A
4. Archimedes' principle; correction for buoyancy in weighing with an analytical balance. 5. Pascal's law. 6. Boyle's law. 7. Dalton's law. . 8. Conservation of ene-gy. 9. Viscosity; definition, units, measurement. 10. Diffusionand osmosis; meaning of these wards. 11. Malleability, ductility, brittleness, toughness; meaning
"..12. A
Tensile strength: Young's modulus, stress, strain, their measurenient. 13. Surface tension; explanation of, measurement of, adhesion and cohesion.
Heat 1. Charles' law. 2. General gas law. 3. Real gas laws. 4. Temperature scales; absolute zero, absolute temperature. conversion. 5. Expansion; correction of barometer scale, anomalous expansion of water. 6. Vapor pressure; definition. variation with temp. 7. Units of heat; B.t.u., calorie. 8. Specific heats; definitions, solids and gases. 9. Latent heat; definition. , 10. Calorimetricmeasurements; mixtures, flow. 11. Brownian movement. 12. Kinetic theory of matter; evidence, pressure of a gas, Boltzmann's constant, equipartition of energy. Avogadro's law. 13. Evaporation: KT explanation, physical factors affecting its rate. 14. Humidity; definitions of relative, absolute, and specific methods of measurement (hygrometry, dew-point apparatus). . 15. Triple point diagram; meaning of the words sublimation. meltina. freezing. va~orization.liauefaction. boiling. 17. Thermodynamic surfaces; gas, unsaturated vapor, saturated vapor, solid phases, their changes with pressure and temperature change. 18. Low temperatures; refrigeration, production of liquid air, ghysical properties of bodies a t low temperatures.
Light 1 Spectrographs; prism, grating, wave length, frequency. wave number. 2. Types of spectra; absorption, emission, line, continuous, spectralseries (Balmer, Lyman, etc.). 3. Excitation potentials. 4. Polarized light; saccharimetry. 5. Index of refraction; liquids and solids. fi. Color of a body. 7. Electromagnetic spectrum.
Electricity 1. Simple galvanic cells; construction, e. m. f., polarization.
Mechanics
Electrical units; ampere, volt, ohm, watt, joule. Electrolvsis: Faradav's laws. S i m ~ lteh e m of ionization. definitions of: electrolysis, electrode, electrolyte, anode, cathode, the Faraday. 4. Electromotive force; definition. Potentiometric measurement. 5 . Dielectric constant; definition, values, measurement. 6. Thermoelectricity; materials, measurements, applications.
1. Length, mass, and time; their units, the standards, tools for measurement, accuracy and errors. 2. Density and specific gravity; ddnitions, examples, methods of measurements. solids and liquids. 3. Pressure; definition, m - n r e m k barometers.
1. Natural radioactivity; alpha and beta particles, gamma rays, electroscopes, disintegration laws, displacement laws, radioactive series.
TOPICS COMMON TO BOTH PHYSICS AND CHEMISTRY
2.
3.
Electron and Nuclear Physics
2. Artificial transmutations; machines, examples. 3. The nuclear atom: Rutherford's work, the Bohr atom. 4 . Isotopes: positive rays, mass spectrograph, heavy water. 5. Gas dischame: Crooke's tubes. ionization ~otentials. 6. X-rays: production, characteristics. 7. Moseley's law. 8. Space lattices: Bragg X-ray spectrometer, von Laue paiterns, types of space lattices. 9. Electron arrangements in atoms. 10. The electron; charge, mass, wave length. 11. Other entities; positron, neutron, photon, mesotron 12. Electron microscope.
Without discussing the individual topics in detail I would, however, like to call your attention to a few of these items. In the snbdivison of heat, item 12 refers to the kinetic theory of matter. The derivation of the equation for the pressure of a gas, namely, p = '/o nm u2, requires the prior knowledge of the physical concept of momentum, impact, and energy. Similarly, throughout much of this same subject matter, the analytical viewpoint can only be attained, and a full understanding of the significanceof the theory by mathematical means, when the student has prior kowledge of purely physical ideas. With the time restrictions so great on the chemical instruction, why not let this subject matter he taughtfirst in a physics course? the section on electricity, items 2 and 3, the student, whether taking chemistry or physics, needs not only to know the definitions of ampere, volt, ohm, watt, and joule, but needs considerable practice in the use of these electrical quantities, such as drill in the use of law in circuit theory, before he can appreciate the electrochemical concepts. The section called electron and nuclear physics is, with the exception of two items, the work of physicists and was developed in physics laboratories. It is needed by the chemist but should he taught by those who originally developed these subjects. chemists take things apart and put them together that again. ~h~~ need to know all about the underholds the atomsand molecules together. standing of this "glue" necessitates a knowledge of the fundamental particles, the electrons, neutrons, and protons the physicist. m y let the physicists teach their own subject matter first? As chemists, you
then have the glorious opportunity of showing how useful this knowledge can he. In conclusion: I believe that chemistry should come first in the liberal arts college because it is less mathematical. I also believe that either chemistry or physics may come first in a technical school, hut that the physics-first sequence offers more advantages than chemistry first. The beginning courses are crowded with subject makter. The attempt to alleviate this difficulty by (1) survey courses, or (2) by careful selection of topics can be, according to my plan, aided (3) by the elimination of those topics duplicated in the chemistry and physics courses.
OFFICIAL BUSINESS 229th Meeting-February 3,1945 Providence College Providence. Rhode Island THE 229th meeting of the N.E.A.C.T. was held a t Providence College on February 3, 1945. The very Reverend Frederick C. Foley, O.P., President of the College, extended the greetings of the College to the Association. Father Edward B. Halton, of the Physics Depdmeut, followed with a lecture and demoustration of "Electrons a t work." The morning Program concluded with a lecture, "Present concepts of heterogeneous catalysis," by W. W. Russell, ~ r o w nUniversity, Providence. After a short business session in the afternoon, Alonzo W. Quinu, of the Geology Dep d m e n t a t Brown University, discussed the topic, "Strategic minerals of New England," and J. Herbert Ward, Head of the Science Department of Providence Classical High School, spoke on " m y students in secondary schools should compete in the annual science talent search competition.'' Harold Farnsworth of Providence, who won honorable mention in the contest this year, described his project to the group.
NEW MEMBER Leroy S. Moody, 122 Winsar Avenue, Watertown, Masachusetts
DEFINITELY NOT "Doyou w i s h p o s t w r colleges o n a concentrated basis similar t o that of the military trainees?" the Unioersity of Illinois asked 202 of its women and 131 of its men students. Eighty-nine per cent of those polled said "no."
EDUCATIONAL CRIPPLES "By the end of 1945 there will be about 3,000,000 young people between the ages of 14 and 22 rcho left school for employment during war years before reaching the age of 18
and before completing high school," says the National Child Labor Committee. This large army will present a n educational problem of serious proportions after the war.
