Joseph K. Obold and Thomas s. Briggs University of Colifornio Berkeley
A Summer Chemistry Program for Teenagers Classroom Work
Teaching chemistry in terms of modern orbital theory to about 300 youngsters, 11-17 years old, was a summer project in 1959 and 1960 for a group of undergraduate and graduate students a t the University of California. The enthusiastic approval of the participants and interested adults in the San Francisco Bay area indicates that a similar program could be successfully carried out in many other areas of the country. The comparative youth of the sponsoring group, and consequent lack of experience in t.he teaching field, was unusual in a program of t,his size and suggests the wide variety of groups which might launch such a program elsewhere. Members of Sigma Chapter of Alpha Chi Sigma, a national professional fraternity in chemistry, planned the program originally to help a small group of boys fulfill t,he requirements for the Boy Scout Merit Badge in Chemistry. The enthusiasm of the Scouts led the fraternity members, supported by the chapter facu1t.y adviser, to realize the importance of a second goal in developing the project-interesting the Scout age group in further exploration into chemistry. Chemistry was introduced t.o the teenagers in a series of eight meetings on successive Saturday mornings during July and August. A typical session included a half hour test, an hour lecture, and 90 minutes of laboratory work. The test and lecture were conducted with the entire group, which then separated into groups of about 20 for the laboratory experiments. Home assignments were an integral part of the course. A short paper on some aspect of chemistry assured some exposure to general scientific literature; freedom to choose his topic allowed each individual to explore an area of particular interest to himself. Each participant was required to present for approval a collection of chemicals found in the home, together with their correct chemical formulas. Finally, an optional home experiment was assigned a t each session for those vho wished to receive extra credit.
The topics discussed ere Atomic Structure, Periodic Table, Bonding, Metals, Xon-Metals, Organic Chemistry, and Solvents. At the eighth meeting a final exam was given over the seven lectures. In the first lecture, the statistical nature of the electron was presented and the weaknesses of the planetary model of the atom was discussed. The concept of spin was introduced as an important atomic force. Spin and other forces were clarified by introducing the principle of minimum energy. Test results showed that t.his lecture was very successful in teaching these relatively new concepts. Succeeding lectures were designed to make use of the ideas presented in the first. The periodic table was derived from an energy level diagram. Bonding was explained in accord with the orbital model, and balloons were used extensively as visual aids. Lectures on metals, non-metals, and carbon chemistry included the use of oxidation st,ates and demonstration of the activity series. Laboratory Experiments
All but two of the laboratory experiments were designed specifically for the course. Equipment required for each student was one beaker, six t,est tubes, 12 in. of glass tubing, two rubber stoppers, one small (250 ml) Florence flask, and a Bunsen burner. Everything except the glass tubing and four test tubes could be cleaned and returned to the stockroom. The instructors chose spectacular experiments to make a strong impression and lead to a desire for further investigation. The instruction sheet for each experiment explained the purpose and the mechanism relating it to the lecture material. S~ggest~ions for further experimentation were often included. The laboratory experiments that best reinforced the lecture material and prompted enthusiastic comments from the classes included:
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Nan-aqueous displacement of lead by aluminum foil when the foil was out into molten lead chloride formed then ignited on contact with air Preparation of a urea-formaldehyde plastic Preparation of aluminum iodide by heating aluminum foil with iodine crystalls (the compound formed was then reacted with water) Preparation of itmmonirnn snx~lpamand sodium amalgam
Home Experiments
The series of home experiment,^ was chosen to utilize household products or easily obtainable chemicals and makeshift apparatus, yet to be as vivid and pertinent to course material as possible. The instructions for these experiments included the theory involved and suggestions for further study. To receive credit, the young student was required to produce yield data on his experiment. Six experiments were presented: Boron oxide from pyrolysis of horio acid Hydrogen, collected in balloons, from the reaction of aluminum foil in muriatic acid Iron (111) chloride from burning of steel wool in chlorine, the rhlorine to be prepared cautiously by acidifying liquid bleach Copper (I) sulfide from the interaction of copper wire and sulfur, including testing the conductivity of both copper and copper sulfide with a train transformer Ipormaldehyde "clock" resetion from the autocatalytic oxidsation of formalin by liquid bleach, including determination of the rate law for thereaction Chloroform from the oxklation of rubbing alcohol by licpid bleach using beking soda ne a buffer
Safety
I t has been mentioned t,hat "spectacular" reactions Irere used for greabest impact. Obviously, the hazards involved had to he thoroughly explained. Safety rules were pointed out a t the beginning of each laboratory period and repeated in the printed instructions. Kot even a burn or cut occurred; it is believed that the boys gained an increased awareness of the danger of unsupervised and haphazard experimentation. Evoluotion of the Program
The first summer, 120 boys enrolled and 70 successfully completed the course. The second summer, the course xvm opened to any boy or girl from 11to 17, and 170 boys and three girls enrolled. Most still were Srouts who wished to fulfill the merit badge requirements. The weekly attendance averaged 120; interest remained high and more than 100 boys received merit badges. Points were assigned for each experiment, test, and special requirement; passing score was taken as 500 of t,he total 1000 points possible, with a certain minimum of participation required in both experimental and academic phases.
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Journal o f Chemical Education
On the basis of expenses incurred the first summer, one dollar was charged each person enrolling. The fee rovered t.he cost of paper, merit badge booklet,^, chemicals, and breakage fees for equipment borrowed from the University. Actual expenses exceeded the money collected by a small amount; this deficit was underwritten by two local professional societies and, in the first year, by the area Scout councils. The paper work involved was handled by t,he fraternity members involved in the course, except for actual mimeographing of stencils. Preliminary publicity releases were prepared and sent to local newspapers and Scout councils in June. During the course, brief r6sum6s of each lecture mere distributed weekly. Instructions for laboratory and home experiments were also given to each st,udent at the beginning of the appropriat,e laboratory period. It should he noted that no more than nine persons were involved a t the instruction and supervisory level. Each of t,hese men was in charge of one laboratory sect.ion or helped to distribute supplies from the stock room; three also took turns preparing and delivering the lectures; the entire group cut st,encils, marked tests, and recorded grades. Iut,erestmingly,the course. was begun, developed, and carried to completion by a comparatively young group, from 18 to 23 years old. The first year all but, one of t,he fraternity members involved had just complet,ed the junior or senior year, and one had completed his first. year of graduate study. The following year five of t.he laboratory instructors were first and second year graduate students and four were undergraduates, including one who had just completed his freshman year. The youth of the sponsoring group was felt to be an asset in building rapport with the Scouts; the small age differential (3-12 years) between "teachers" and 'Lpupils" perhaps encouraged the natural inquisitiveness of the Scout,swith less effort than older instruct.ors would have required. In any case the infectious enthusiasm of the sponsors was one of the most important factors in the presentatmionand reception of the program. A group of some 20 Scouts from the first year program were invited to continue meeting on Saturdays during the ensuing fall semester, with three of the fraternity men. The advanced program had two objects: to train laboratory assistants for the course to be given the following summer, and to stimulate and channel the special interests of these st,udents. The "laboratory assistant" idea was of great aid to the laboratory instructors during the second summer. The total value to the individuals of this select group cannot of course be evaluated; but t,he continued interest, outside study, and penet.rating questions of some of the participants of these completely volunt.ary sessions were very encouraging.
