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LINDAWOODWARD The University of Southwestem Louisiana Lalayette,LA 70504
chemistry for kids Elementary Education Ambassadors Avi Ornstein
Berlin High School, 139 Patterson Way, Berlin, CT06037 The best way to learn something is to explain it to someone else. Every teacher has gained this insight through personal experience. In this article, I discuss a system I have developed that extends this aspect of learning to my students. By no means am I the first to follow this path, but my experience may help interested teachers to avoid having to "reinvent the wheel". My high school science students are required to select a basic subject concept by the end of the first half of the school year. (In my chemistry classes, it must be a basic concept dealing with chemistly. Sample topics are listed in Table 1.)They then develop a brief lecture and a series of demonstrations and hands-on activities to explain this concept to younger audiences. After performing to my satisfaction, including advice and modifications, they present the unit to interested elementary school classes. The assignments given to the students are listed in Table 2. The preparation includes supplying each student with a copy of the "Minimum Safety Guidelines for Chemical Demonstrations", prepared by the ACS Division of Chemical Education (11,and going over it in class. For each presentation, I also monitor what materials are used and how they are transported, what hazards are associated with the activities, what might go wmng and what should be done. Unsafe activities either are replaced by safer alternatives or vetoed. The elementary students are not exposed to any risks that exceed their everyday, home environment. To offer clarification, let me discuss one presentation done by two sophomores. Their topic was pressure. They began with a basic, descriptive lecture, defining the terms used. It lasted only a few minutes. They then had four demonstrations. One used a "potato gun" to show how decreased volume causes pressure to increase. They then placed a balloon over an open soda bottle and showed how the gas released blew up the balloon. They showed the existence of atmospheric pressure by inverting a soda can containing steam into cold water. The final demonstration consisted of placing half of an Alka-Seltzer tablet in a film canister containing some water, covering it, and standing back. For the hands-on activity, the students learned how Table 1. Sample of Chemistry Topics
Acids and Bases
Indicators
Chemical and Physical Changes Phase Changes Chemiluminescence
Polymers
Crystals Density
Pressure Solubility
Gas Laws
Surface Tension
500
Journal of Chemical Education
straws actually work by trying to drink from a cup with two strawsone in the cup and the other outside. I had them replace the third demonstration with the simple example of drinking from a juice pack, which more safely showed the presence of atmospheric pressure. The safety aspects of the first and last demonstrations were discussed, and they wore safety glasses while performing them. It was suggested that they ask the students to predict in advance what would happen. The appropriate audience was decided to be second and third grade students. The quality of their presentations was good, but it improved as they went along, due both to gained confidence and positive suggestions included in the evaluations by the elementary teachers (Table 3). At first this program was an optional assignment in my higher level chemistw classes. 1r then became a required assignment in those zasses and later was required of all of my students. It has now returned to being an alternative to a research project for all level classes. If they miss any scheduled deadline for the demonstration project, they are required automatically to switch to the research project or points will be deductedfrom their fourth quarter grade. On the other hand, there is no "grade stigma" if they do become "science ambassadors". While the presentations are evaluated, they are not graded. The scheduled deadline ultimatum prevents delays that can grow exponentially. For the students who participate, this is a win-win situation. The high school students develop a better underTable 2. Student Demonstration Assignment 1. Select your topic before the end of the second marking period.
2. Research the topic. Find at least two demonstrations and one hands-on activity. Have them approved by February 4th. 3. Prepare yodr verbal and v sdal presentaton. Check OLI all safelyconcerns. Perlorm 11tor yobr leacher by March 4th.
4. If necessary, make appropriate modifications until it is ap
proved. Decide on the appropriate audience level. 5
Elemenrary scnools w II oe contacted ano meresled leacners
wdl Then work OLI wtln YOJ a scnmu e 01 wnere an0 wnen the presentallon(s)wl I be maoe YOJ rnLst contact tnem wltn n two weeks
of when you are notified of their interest
6. The teacher($ will fill out evaluation forms when you give the
presentation. These are for evaluation purposes and will not affect your grade. 7. Any studenl who does more man two presentallons (or to~r 'n the case of a team ol two a~dents) w I earn extra credit on tne fourth marking period grade. [Note:Regarding #7, 1 explain to the students that if they do the preparation but less than the "required"number of teachers are interested. this will in no wav reflect won them.
Table 3. Evaluation Questions
How well did the presentation match the topic title? HOW well did it keep your students' attention? Do you have any suggestions for the presenter(s)? Did you feel the presentation was beneficial? Do you feel this program should be continued, extended, andior modified?
What is your overall evaluation of the presentation? standing of a particular wncept, they increase their selfesteem, and they are exposed to the other side of the classroom. The elementary students are fascinated by the student presentations. I t heightens their interest and improves their foundation in science. The elementary teachers, many of whom are weak in science, find that this
improves their class program and shows them demonstrations and activities that they can incorporate into their curriculum. The program definitely requires an investment of time and effort on mv " .art. because I meet with students either during my free or a f ~ cschool r to see their present*,. tions. Thev nlio are allowed release time from one class. if needed, for doing their presentation. Because it is a sehoblrelated activity, parental permission is required. Even so, it has proven to be worthwhile. The evaluations by element a m school teachers have been consistentlv and . ~ositive. . rn;studmts have found the experience to he rewarding, especiallv when they see the fncesof the elementary school Literature Cited I. J . Chem Educ 1988,65,721
Volume 71 Number 6 June 1994
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