NOVEMBER, 1953
581
A MODIFIED SILVER TREE WILLIAM H. R. SHAW and B. T. NOWLIN University of Texas, Austin, Texas
INA recent issue of
THIS JOURNAL, D. I. Gleimi dis- and cut diagonally, leaving a triangle, 6 X 3 inches, of cussed the history, beauty, and elegance of silver trees double metal with the folded edge upright. The two as a means of demonstrating displacement reactions. sheets are then cut into narrow strips horizontally It is the purpose of this communication to describe from the diagonal to within '/, inch of the folded edge. The strips are then opened out to form the branches of a tree, as shown in Figure 1. The two lowest strips are wrapped about the trunk to form a base which is inserted in the hole of a mbber stopper. The tree is placed in a 2-liter beaker containing a 2 per cent silver nitrate solution."
Figure 1.
Tree Constructed of Sheet Copper
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a modified ~rocednrefor making silver trees that ensbles quite large specimens to be grown. The fragility
Procedure: To make a, tree 6 inches tall. a thin sheet2 of copper, 6 X 6 inches, is folded in the middle GLEIM,D. I., J. CHEM.EDUC., 30, 151 (1953). ' Electrolytic copper may be obtained from any ohemied house.
~i~~~~ 2.
~ f t = rmmersion =
in a silver ~
i
t solution ~ ~ t
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Figure 2, obtained forty minutes after immersion, shows the spectacular growth of a typical specimen. WALTON, J. H., ibid., 8,303 (1931).
PACIFIC SOUTHWEST ASSOCIATION OF CHEMISTRY TEACHERS
CHEMISTRY A T SAN FRANCISCO STATE COLLEGE, 195253
THE Spring meeting of the Northern Section of the PSACT was held a t San Francisco State College. The program consisted of three discussions of current programs a t S. F. S. C. The topics were: (1) "The General mucation Program," introduced by Maurice Amaden, Associate Profmor of Physical Science. (2) "The Chemistry Major" by Stanley W. Morse, Chairman of the Division of Natural Sciences. (3) '(The General Secondary Credential in physical Science" by Robert Stollberg, Associate Professor of Science Education. Notes on the three presentations follow herewith.
physical sciences for the science courses of the General vroeram. Education .
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THE CHEMISTRY MAJOR
All majors a t San Francisco State are built upon t,he colleee General Education Droeram or, if a student transfers t o the college with 30 more units, upon the State program of General Education. Since the State program is more flexible than the local college program, transfer students can more easilv meet the needs of the chemistrv than entering as freshmen. However, a well qualified entering freshman can complete both the general education program and the chemistry major in~fouryears if his four-year academic GENERAL EDUCATION PROGRAM program is well planned. The General Education program at sari Francisco There are no course reuuirements in mathematics or State College now constitutes the lower-division re- foreign languages, ~t is recommended, however, that a quirement for all students entering the college as fresh- reading knowledge of ~e~~~~ or another foreign lanmen. As a remlt of numerous conferences, the faculty guage be obtained by any student planning to take adhas developed a program based upon student needs, vanced work in chemistry. A working knowledge of which are grouped under four broad classifications: the calculus is necessary, ~h~ student may achieve individual development, socio-civic, home and family, these twocompetencieseither by individual study or by and occupational studies. This has resulted in the courses taken as electives. These courses are not listed establishment of a definite semester sequence of such in the presentchemistry major program. offerings. For example: (a) The Low Freshman semester required 10 units: personal and occupationa~de Minimum Chemistry Major Requiremats for A.B. Degree (Units) Year of general inorganic including qna~idtive... . . . . . . . . . 10 velopment (3 units), basic communications ( ~ 1 ,units), ~ Year of general physics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 human biology and health (4 units)~and physica1 edu- Organio lecture.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 cation ('/z unit). (b) The High lhshman semester re- Organio preparations.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 quired 9 units and recommends 2l/2 more: personal Quantitative analysis.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 9 and occupational development (3 units), basic corn- Electives from upper division chemistry.. . . . . . . . . . . . . . (. . munications (21/2units), culture and society (3 units), 36 physical education ('/2 unit), with creative arts (2 It is believed that the establishment of a minimum units), and recreation unit) recommended. The objectives which pertained to science were or- major draws more liberal arts students into the field, ganized by the Natural Science Division into three some of whom become interested in continuing the work courses totaling 10 semester units: Biology 1, the . after graduation, either by working in chemistry or dobiology of man, 4 units; Mathematics 30, mathe- ing graduate work. Students with the minimum matics in human affairs, 2 units; and Physical Science major would seldom be recommended for a position 34, the physical world, 4 units. These three Science and, naturally, never for graduate work. The typical major student will probably include these Division courses are the prescribed units in science for graduation for all students entering the college as fresh- electives: advanced organic (3 units), organic analysis men. The only exceptions to this requirement are (3 units), advanced inorganic (3 units), physical made for preprofessional students-medicine, dentis- chemistry including physical chemical measurements try, pharmacy, veterinary medicine, etc.--and for those (5 to 8 units), advanced quantitative analysis (3 units), entering the Clinical Science program. These students and probably some work in biochemistry or industrial may substitute regular college courses in the l i e and chemistry. Many students include physics courses 982
583
NOVEMBER, 1953
such as electrical measurements, thermodynamics, or modem physics. This work, although not required, is taken as elective units through advice. The chief diiculty for entering freshmen is the block of 10 to 11 units of General Education in each of the first two semesters and slightly less in the third and fourth semesters. This makes it difficult t o schedule the necessary mathematics, physics, German, and first year chemistry early in the college program. However, it can and has been done by well prepared students. College authorities believe the A.B. major plan is satisfactory as now handled and hope to establish soon a B.S. chemistry major, in which minimum requirements can be more rigid and similar to the A. C. S. recommendations for the major.
of science to permit him to teach general science satisfactorily. The new teacher will find advanced, preengineering types of courses in physics and chemistry something less than essential. Instead, he will profit. from a broadened familiarity with the applications of science in daily life and in industry. He will need practical experience in organizing, purchasing, maintaining, and repairing science equipment. Fmally, since he must exploit the interests and activities of his students, he should have a working knowledge of some of the hobby-like enterprises related t o science. The following abridged chart summarizes the requirements for the major and the minor in physical science for the secondary teaching credential as set forth by San Francisco State Collegs:
SECONDARY TEACHING CREDENTIAL
Units required Minor
Major Several timely questions were emphasized under this A. Lower Division heading, including the following: 1. General Education, including: fa) Human bioloev and health (lee.) 4 (1) What kind of vosition will the new teacher have? ~hs'chancesare three-to-one that he will start (bj The physicalworld (lec.) 4 (e) Mathematics in human affair8 (kc.) 2 his teaching a t the junior high-school level, (grades 2. Inorganic chemistry (lee. & lab) 5 seven, eight, and nine) whether or not he so desires. (let. &lab), or 3, Applied general There are more students a t this level than in the senior (a)Inorganic chemistry & qualitative high school, and more required science courses. analysis (lec. & lab) ( 5 units) ( b ) Organic chemistry (lec.) (3 units) Furthermore, experienced junior high-school teachers (e) Organic preparations (lab) (3 units) will often receive preferential treatment when it comes (d) Quantitative analysis (lea. & lab.) to filling vacancies in the higher grades. ( 3 units) (2) What courses will the new teacher teach? Be4.. General ~ h.v a i r sflee., & lab), (,~2 semes- ~ = caisk the new teacher is likely to teach a t the junior ters) 8 3 5. General biology (let. & lab) high-school level, he is apt to teach general science, inB. Uppel Divisirm cluding not only physical and life sciences but also mawith adviser) Choice (in terial from the fields of health, safety, and the like. from the fallowing courses: 12 (a) Meteorology (lec.) (3 units) Even if he does teach in senior high school, he will (b) History of the ~. physical sciences teach a varietv of science courses. These will include (lee.) (3 units) the traditionai courses such as physics and chemistry (e) The science of photography (kc. and possibly biology, and also less common ones such as & h h ), ~4 nnits) - .-. -~~~.-, integrated physical science, consumer science, elec(d) Industrial chemistry (leo. & exoursions) ( 3 units) tricity and radio, and aviation science. He may also (e) Modem . . physics (kc. & lab) ((3 teach mathematics or other courses even farther reunits) moved from the field of science. Only in the few large (f) Either radio physics (lec. & lab) high schools will the new teacher escape the need for (3 units) or electronics for teachers (iec. & lab) (3 units) versatility. Furthermore, he may be called upon to supervise science, radio, and photography clubs, and C. Graduate Study 1. Physical science for secondary teachers other extra-class activities related to science. (lec. &lab) (3) -3 . . What qz~aliJicationsm'll the teacher need to meet i ~ ~ (exolusive ~t $ i ~~~~~~l~~ d ~ ~ these demands? Every prospective secondary science ~ 36 teacher should be sufficiently a t home in the broad field tion credits)
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