RON
edited by: DELORENZO
Mnddle Georgia College Cochran, Georgia 31014
Simple Techniques to Generate Chemical Applications that Arouse Student Interest Ronald DeLorenzo Middle Georgia College, Cochran, GA 31014 I t is helieved by some that a greater retention of students will occur if they feel good about their learning process. There are certain variables that students believe have a positive effect on their learning or, a t least, on the way they feel about their learning experiences. Students feel that it is very important for them to recognize how a particular course fits into their career, their vocational growth, and their personal growth. Thus, a sense of relevancy should he built into the course structure. The blending of chemistry with a variety of current applications tends to accomnlish this eoal. I t laces both chemistw and student into a ftl6i1iarsetting: it siimu1uit.s student i n terest:. it .uruduces an educated versus a tra~nedstudent. In general, applications are more interesting to learn (and more fun to teach) than a collection of facts and theories isolated from the surrounding world. I have accidentally discovered asimple technique that has generated a wealth of applications for use in my classrooms. I would like to give you the rationale behind this simple technique before I explain it. My rationale involves a review of ideas with which you are probably familiar. ~~~
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We are living in an age of increasing specialization. The so-called information explosion has produced a corresponding ignorance explosion. As we specialize in a narrow aspect of science or chemistry, we find ourselves a t a very elementary level in other areas. Just as an obstetrician would not think of substituting for a neurosurgeon during an operation, the majority of chemists are not only ignorant of many areas of chemistry (and understandably so), hut they are also ignorant of many areas of science outside of chemistry (such as physics, biology, astronomy, geology, and computer science). How many chemists could do well in even a high school final examinat ion in ihcse various areas? Very few collvye chemistry teacher* have ever heard of the publicition Science World. It's a junior high school magazine published by Scholastic, Inc., of New York City. I first discovered Science World when my wife, Mary, brought home an issue that she had come across at the junior high school Resented at the 1981 American Chemical Society National W i n g , New York City.
Volume 59 Number 6 June 1982
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where she was teaching. This was about 15 years ago. At that time I had never had a hiolom course or a aeolom course. and I found the articles in these &ens fascinating ar;;jeducational. 1discussed some uf therhemistrv related articles with 1'h.U. chemists who proved to be as uninformed as I and equally as fascinated. After I graduated and began teaching, I continued to read Scrence M'urld and, after about three years, intruductd maI C P article on circadian rhythm (the terial from ~ S C I P IWorld so-called himlogical clock within all li\,ing organisms) to my eeneral chemist rv class. The lecture was mort: sucn~ssl'ulthnn i ever dreamed it could he. I am sueeestine. as a first sten in the techniaue of eeneratine material ;;f interest to yourstudents, suh&bing to and reading elementary science periodicals such as Science World. This sounds like such a simple idea that I'm almost embarrassed to submit it to you. However, I'm not aware of many others doing this. I discovered it by accident, and it has worked for me. I would not he surprised if you are skeptical because even my best friends have taken this advice politely, only to confess years later that they have rediscovered it on their own. These elementary periodicals have a unique goal: to try to arouse an interest in science in a population that 1s rrl;nively uninterested. Many grade schuul and junior high schuol stw dents could not care less ahout science. 'l'he articles in these magazines must be interesting as well as accurnte. Kecentlv. a whole glut oinew science mnmzines has hit the market, most of which are aimed a t the nonscientist or nonchemist. For exam~le.there's Discouer, Sciquest, Science News, Science 80, Hnd Next. Other similar sburces include the science section of Time and Consumer Reports. Most of these magazines have highly condensed sections for economy of time, e.g., Shorts, Notes, Capsules, Concentrates, News in Brief, Currents, Up Front, and Notes From All Over. There is a practicality involved with the elementary periodicals. I t is easy to tell what their articles are ahout by reading the titles in the table of contents. I have always been fascinated with dinosaurs hut could have easily missed a recent article in Science entitled "Extraterrestrial Cause for the Cretaceous-Tertiarv Extinction. Exnerimental Results and Theoretical lnterpr&ations." when-science World covered the same storv. -. t h,w- "eave it the followine- title: "Were the DinosaursJapped by an Asteroid?" When it came time for me to list the sources of the ideas that I used in my hook, I noticed that 25% of the references were from Science World. To its credit, 50%of the references were from the JOURNAL OF CHEMICALEDUCATION.The other 25% were equally distributed among the periodicals I have already mentioned and some others which I hesitate to mention. . . such as Playboy. After vou have found an elementam science neriodical. vou are veryiikely to come across an article or twothat reallykxcites you, or that you think will really he of interest to your chemistry students. How can you fit the information found in this article into your lectures? As chemistry teachers who teach general chemistry, you are blessed with a survey course that covers so many different topics that almost anything you read can be related-to one of thevast numher of topics covered in a general chemistry course. There are many ways in which new information can be inserted into your existing lecture notes. The trick is to insert this material without using up too much time. The lack of time is generally a major problem for most of us anyhow. A common concern is that there is already too much material to cover and not enough time in which to cover that material. One wav to insert interesting- a .. ~ ~ l i c a t i o ninto s a lecture without consuming vul~mhletime is to use the applicatiirns in example prohlemc. Many of the example prot~lemswe uce deal
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with nonexistent artifacts and imaginary data. Why not substitute real artifacts for the nonexistent artifads and actual data for imaginarv. data? For examnle.. I have found that the Shroud of'l'urin is of inrerest to most of my students regnr~lless of their relieiuus or nonrelieious inclinatims. c'l'he Shroud of Turin is a lkfoot linen cloth that hears the image of a e that the shroud is the burial crucified man. Some n e o ~ l claim cloth of Jesus ~ h r i s t1tj & easy to calculate what the carbon-14 radioactivity of the cloth must be in counts per minute per gram of carbon if the cloth is actually 2000 years old. This calculation can substitute for one of the similar radiocarbon examples that you are probably already using. There are many interesting ideas even in nonscientific periodicals that can he used to arouse the interest of students. The Reader's Digest recently published an article that discussed the meanings of little-known words of the English language. "Berm" is one such word. What is a herm? Well, if you dig a hole, you usually place the dirt you dig from the hole into a pile next to the hole. The space between the pile of dirt and the edge of the hole is the herm. Really! Instead of asking your class to convert ten inches into centimeters, why not ask them to express the length of a ten-inch berm in centimeters? Admittedly, you will frequently have to do some additional digging, because many of these articles are not very specific or scientifically detailed. This will force you to seek out, for example, a specialist or specialty text for greater amplification. This can he fun as well as educational. To illustrate, I read what I considered an interesting article in a maeazine called Next about a nrofessor of architecture a t the University of Texas who figured out a way to grow buildings and other "concrete" structures underwater. The resulting structures had the same color and texture of concrete, were at least 30%stronzer than concrete, and were 1000 times cheaper than concrete. The material "grown" is primarily magnesium hydroxide and is formed by making cathodes out of metal mesh in the form of the desired structure. Electrolysis makes minerals in the seawater adhere to the mesh. Now, I know that cathodes attract cations and cause them to plate out of solution, hut I was perplexed as to how it was possible to plate out of solution a salt such as magnesium hydroxide. It was a real puzzle for a while, and it was only upon discussine this nuzzle with other instructors that the mechanism for &is became clear. (The mechanism was not explained in the original article since the article was not aimed at chemists but at the lay public.) The electrolysisof the ocean to form at the cathode. Other cations. water caused hvdroeen . such as magnesium, are attracted into the region of the cath: ode even though they do not plate out. Also, as hydrogen is evolved, the hydroxide concentration in the immediate vicinity of the cathode increases. The increased magnesium coocentration imd the increastd hydroxidr runnmtmtion hecome such that the product ~t their concentrations exceeds the K., of maenesium hvdroxide:. maenesium hvdroxide precipiiates at ihe electroie. In summary, students enjoy being able to relate to their courses. There is a wealth of material available in elementaw science magazines in areas other than chemistry. Read these articles with the goal to further your own education and to find a place for this new information among the countless topics discussed in eeneral chemistry. A minimum of extra time is needed if thenew information is made a part of existing exa m ~ l nrohlems. e ~ h e i e s u l t sof this effort may be more interesting classes for both vou and vour students and, in turn, a higher retention of students at yo;r college and, perhaps more importantly, a better informed public! %.
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