In the Classroom
Chemical Demonstrations as the Laboratory Component in Nonscience Majors Courses
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An Outreach-Targeted Approach Charles E. Ophardt, Michelle S. Applebee,* and Eugene N. Losey Department of Chemistry, Elmhurst College, Elmhurst, IL 60126; *
[email protected] Traditional chemistry laboratory exercises in courses for nonscience majors appear limited in capturing student interest and motivation. An article from this Journal reviewed college chemistry laboratory practices and suggested getting away from “cookbook” activities (1). The Department of Chemistry at Elmhurst College has taken an alternative approach to the traditional laboratory for one of our nonscience majors’ courses. Students in Chemistry in the Natural World: Demonstration Focus learn basic chemical theory by participating in a chemical demonstration-based laboratory that incorporates outreach activities. Students work in the laboratory to create and practice chemical demonstrations based on topics they are studying in lecture. Then twice during the semester, the class performs chemical demonstration shows at area elementary schools. Initially the demonstration-focused laboratory was conceived as a month-long January-term course in which elementary education majors could fulfill state teaching requirements in the physical sciences. In this format only a small fraction of time (6–8 hours out of 42 class hours) was spent presenting general chemistry concepts. Most of the time was spent in the laboratory, where students developed and practiced demonstrations, learned concepts, and created explanations and visuals for each demonstration. Each week the work culminated in the students performing different demonstration shows at local elementary schools. A reduction in the science credit required by the state for education majors eliminated the audience for the monthlong course. So after successfully running the month-long course for 12 years, the demonstration–outreach laboratory experience was applied to the nonscience majors’ general education chemistry course, incorporating traditional, formal lectures (42 lecture hours per semester plus 3 hours of lab per week). Incorporation of the demonstration-focused laboratory into a standard course with all of the same methodology to fill the physical science requirement for elementary education majors is described in this article. The Chemistry in the Natural World: Demonstration Focus course provides students a unique and active-learning experience in science. In place of traditional cookbook-based laboratory experiments that often fail to serve nonscience majors’ interests or understanding level, the lab for this course revolves around forming deeper understanding of fundamental chemical theory through demonstrations. The use of demonstrations in science to inspire or explain is not new (2–4). However, instructors struggle with introduction or incorporation of demonstrations into their teaching, fearing a loss of time for covering material, and wondering whether demonstrations really enhance learning (4–6). By having dem-
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onstrations as the laboratory focus, students are allowed to take the time required to benefit from the activities. Students experience numerous concrete illustrations of a concept that is reinforced in lecture. This approach gives students multiple chances to understand a particular theory or concept and holds their interest. Furthermore, the students pay more attention to what is being learned in lab because they know they must explain this information to elementary students. Methodology The students in the demonstration-focused course are expected to fulfill these learning objectives: understand and explain chemical principles, develop oral and written communication skills, and develop and modify demonstrations to practice aspects of the scientific process. While the course is open to all nonscience majors, education majors obtain additional benefits. These students gain insight into teaching science at the elementary-school level, benefit from an initial experience of working with elementary students, and gain the knowledge and confidence to later incorporate demonstrations into their student teaching and future teaching careers. This nonscience majors’ course meets for three 65minute lecture sessions and one three-hour laboratory session per week. During each lab session, each student selects two unique demonstrations to prepare and perform for the class that lab period and later at the demonstration show. The demonstrations are found in unpublished compilation books from previous classes, a course Web site (7), published books (8–10), and Tested Demonstrations in this Journal. A list of 40 demonstrations typically selected for demonstration shows can be found in Supplemental Material.W The demonstrations cover a breadth of topics: polymers, the four types of chemical reactions, polarity, density, and gases to name a few. Six specific demonstrations are done at each show: liquid nitrogen, nylon rope, solid water, polyurethane foam, hydrogen balloon,1 and elephant toothpaste. Students are encouraged to modify or adapt the demonstration to illustrate the same theory using different chemicals or techniques to illustrate the scientific method. Also, the instructor may suggest specific demonstrations to students who are struggling with certain concepts. The instructor ensures a cross section of demonstration topics and eliminates duplication in the activities picked by the students in each performance group. Finally, the instructor or a laboratory assistant meets with each student (approximately 12 students per class) to assist him or her with concepts and molecular-level explanations, and to critique and suggest presentation or performance ideas.
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In the Classroom
After three weeks of demonstration preparation the students are split into groups of five to six students to perform a dress rehearsal of the demonstration show at the college. Each student does four demonstrations, resulting in 20–24 demonstrations per show, lasting 45–50 minutes. The students rotate through their demonstrations, working at plastic-covered tables with self-adhesive shelf liner paper-covered boxes as stages and light boxes designed to highlight the demonstrations for easier visibility. At this time the students receive feedback from the instructor and their classmates. The instructor assesses each student’s performance in the practice shows performed at the college. A grading rubric has been established based on the criteria listed in Table 1. The following week the students go to a local elementary school to perform their show for two different groups consisting of 20–60 third, fourth, or fifth graders in the gymnasium, cafeteria, or multi-media–art room. A range of schools are visited, including local Elmhurst schools, primarily minority schools in the college’s satellite program associated with our Education Department, and parochial schools. This five-week cycle is repeated twice during the semester. Additional details of laboratory outline, general supplies carried, and assessment criteria can be viewed in the Supplemental Material.W Two important logistical issues must be addressed with a lab of this type. First, in the lab, we have found the use of an upper-level undergraduate laboratory assistant is essential because of the large number of different activities occurring at one time. The lab assistant helps the students locate supplies and answers other questions. Most demonstrations are checked and observed by the instructor or lab assistant prior to the first performance in the lab. Second, safety issues must always be addressed when performing demonstrations both in the lab and at the elementary school setting. Safety is stressed throughout the show by noting special procedures, wearing of goggles and gloves (when appropriate), and that kitchen-chemistry demonstrations should not be done at home without parental permission and supervision. Special care is used in selecting demonstrations so that a majority of the demonstrations done involve household chemicals or solutions at diluted strengths (see Supplemental MaterialW). Our students are instructed about any special disposal concerns associated with a demonstration and waste bottles are taken to each school to return these mixtures to the laboratory after the show. No waste is left at the elementary school where young students can come into contact with it. Fire extinguishers are on hand at all times, although only very few of the demonstrations use a flame. Hydrogen balloons are generated on site through reaction of zinc and dilute HCl, to lessen the risk associated with transportation (11). The elementary children are alerted prior to the hydrogen balloon explosion, which provides the finale to the show much to their delight. Furthermore the appropriateness of flame or explosion demonstrations is discussed with elementary school officials prior to the show date and each room is assessed for safety concerns (ceiling height, space between audience and performers, etc.). If the demonstration cannot be done in a safe way, owing to limitations of the site, the demonstration is removed from the show.
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Table 1. Demonstration Presentation Grading Criteria and Expectations Criterion
Expectations
Introductory comments
Have an attention-getting statement or two.
Commentary during demo
Report on important observations without forecasting them, act surprised when reaction occurs, and ask questions such as “What do you think will happen if…?”
Explanation
Clearly explain the science concepts in the demonstration.
Demo skill and poise
Demonstrate organization, present demo in a logical order, read minimally, and speak clearly and slowly.
The preparation of demonstrations represents a selfguided, deductive method of learning. The concepts associated with each demonstration are deduced from the observations made by the student and are then used to develop his or her own explanations. Although concepts are often repeated, each example and explanation is unique. This means that students represent chemical concepts in their own words and verify them as correct with the instructor, instead of silently assuming that what they believe is true. The instructor can also identify and correct each student’s individual misconceptions in the relaxed atmosphere of lab. This process also eliminates the fears students have about asking questions in front of their peers. Students are required to write a demonstration report for each demonstration prepared. These reports include the following: the materials and solution preparations, instructions for presentation, introduction or story, explanations of the scientific concepts at both college and elementary-school levels, safety and disposal notes, and references. Students also prepare a poster to aid in explanation of the demonstration. The posters include drawings of equipment, visual representations of observations expected, chemical names, and formulas, reaction equations, and simple concept explanations. Requirements and guidelines for reports are supplied in the Supplemental MaterialsW as part of the student handouts. Results Because this lab is unique compared to other laboratory classes on campus, we wanted to investigate how the college students felt about the demonstration-focused laboratory compared to traditional laboratories offered from other science disciplines (biology, physics, and geology) at the nonmajor level. In addition, we wanted to ascertain how well the learning outcomes were met in this full-term course that has been taught for two years with two classes per year. On a prepared questionnaire, students were asked to rank specific qualities of the chemistry laboratory experience and also were asked to compare this course to other nonchemistry science courses with a more traditional laboratory. Results for the
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demonstration-based laboratory course qualities are listed in Table 2. A 1-to-5 scale was used, with 5 being excellent, 2 being poor, and 1 reflecting no opinion. All of the average scores report that the laboratory was effective in reaching our outcomes. The lowest reported area is in written communication, where the only written exercises were demonstration reports, written in a scientific manner. The comparison of the demonstration-focused laboratory compared to traditional science laboratories (biology, physics, or geology) is shown in Table 3. A scale of 1-to-5 was again used, with 5 favoring the demonstration laboratory and 1 favoring the traditional laboratory. Statistical analysis of all four questions indicated that means were significantly greater than 3, which shows most students preferred the demonstration-based laboratory to the traditional laboratory in the categories sampled. Individual students found different advantages or preferences in this course. Yet, regardless of major, a majority of the students found this chemistry course to be practical and interesting. Below is a small sampling of comments about the demonstration-focused chemistry course, each focusing on a different aspect. I found simple labs that explain topics to students in simple, understandable terms. I used some of the labs I learned in CHM 100 during student teaching and the students loved them and were able to explain the concepts weeks later describing the lab.—Elementary Education major The freedom we were given to choose and perform our experiments. It made us have more control of our progress in the class. It also helped us to be able to try things out and experiment with them to determine if and how they worked.— Speech–Language Pathology major It taught me chemistry in an easy-to-understand, simple manner. As an English major, science has never been one of my strengths, but I found myself enjoying this chemistry class more than some of my English classes, and it was the first ‘A’ I got in a science class ever. I learned more about chemistry in this one course than I did throughout high school.— English major
Many of the students felt some apprehension about presenting in front of a group of elementary students. However, most of the fearful students returned from the first show more confident and excited by the experience. The college students were impressed with the elementary students’ willingness to ask questions and their ability to relate the demonstrations to activities done in their classroom prior to our visit. The college students also appreciated the children’s interest in the college students themselves and their inquisitiveness about college in general. Conclusions This unique laboratory experience has had numerous positive outcomes. It has greatly influenced the lecture portion of the course, in that students often have “hands on” experiences with many of the concepts prior to discussing them in lecture. In other cases, the instructor performs a demonstration in class as a lead in for the lecture; thus, the lecture material builds from a visible, concrete experience. The students also get excited when they understand a little about 1176
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Table 2. Ratings of the Chemistry DemonstrationFocused Laboratory on Course Outcomes Average Score (standard deviation)
Laboratory Outcomes Learning basic chemistry concepts
4.67 (0.48)
Improving oral communication skills
4.17 (0.79)
Improving written communication skills
3.83 (0.87)
Making connections between chemical theory and concrete examples
4.56 (0.70)
Overcoming your fears of chemicals
4.11 (0.52)
Strengthening your interest in science
4.28 (0.75)
NOTE: 5 = excellent, 4 = good, 3 = fair, 2 = poor, 1 = no opinion (No opinion responses were excluded from statistical analysis.).
Table 3. Comparison of Demonstration-Focused Lab (CHM 100) versus Traditional Science Labs Average Scorea (standard deviation)
Area Interest in activities performed on a given day
4.42 (0.79)b
Level of understanding of laboratory material
4.08 (1.00)c
Confidence in working in the laboratory
4.00 (1.20)d
Freedom to learn at your own pace
4.00 (1.35)e
a 5 = better in CHM 100, 4 = somewhat better in CHM 100, 3 = no preference in either lab, 2 = somewhat better in other science lab, 1 = better in other science lab; t-test, p values: b6.19 , p < 0.001, c3.77, p = 0.003, d2.87, p = 0.015, e2.57, p = 0.026.
the material ahead of time. As an instructor, it is easy to draw on the experiences the students have had in lab and most topics have multiple examples among the demonstrations. This provides a unique opportunity for the instructor to question students on the theory being presented because they have seen a concrete example, which is a basis for explanation. The benefits of combining chemistry and outreach programs are obvious: community interaction and science education are beneficial to the students, the college or university, and to the public at large (12). However, almost all of these programs have involved the use of chemistry majors (13–18). Having nonscience majors introduce chemistry to youth groups is an effective way to show the importance of science to one’s life, regardless of an individual’s interests. More importantly the course gives the college students an opportunity to interact with their community. This creates a strong bond between the institution and local schools, as well as between the students and their community. The laboratory-focused nonmajor class has proven successful for all participants. The instructors have noted an increase in student interest in material, a willingness to ask more questions, and a better understanding of scientific principles. Also, the large number of students who have used chemical demonstrations and demonstration-based activities during their student teaching illustrates the effectiveness of this labo-
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ratory method in their careers. The nonscience major college students are exposed to chemistry in a way that is innovative, fun, and relates to life experiences. They clearly enjoy the outreach activity. The elementary students are exposed to science in a fun and interesting manner. Because chemical principles are often repeated throughout a show, the younger students learn basic chemical definitions and can recall examples of principles (cognitive learning). They also get to see both science and college life in a fun and interactive manner (affective learning). The elementary students exhibit a new excitement in science and college, asking questions about both at the end of the show. This course demonstrates the beauty and commonality of chemistry in everyday life, and it alleviates the fear of “chemicals” among this group of nonscience friends. W
Supplemental Material
Instructions to the students, sample laboratory syllabus, list of commonly run demonstrations, and commonly carried equipment are available in this issue of JCE Online. Note 1. Hydrogen balloons are prepared on site via reaction of Zn metal with 6 M HCl in a vacuum filtration flask, producing balloons 4–6 inches.
Literature Cited 1. Hiloshy, A.; Sutman, F.; Schmuckler, J. J. Chem. Educ. 1998, 75, 100–104.
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2. O’Brien, T. J. Chem. Educ. 1991, 68, 933–936. 3. Serianz, A.; Graham, D. J. Chem. Educ. 1988, 65, 356–357. 4. Meyer, L. S.; Schmidt, S.; Nozawa, F.; Panee, D. J. Chem. Educ. 2003, 80, 431–435. 5. Deese, W. C.; Ramsey, L. L.; Walczyk, J.; Eddy, D. J. Chem. Educ. 2000, 77, 1511–1516. 6. Beall, H. J. Chem. Educ. 1996, 73, 641–642. 7. Elmhurst College Demonstration Home Page. http:// www.elmhurst.edu/~chm/demos/index.html (accessed May 2005). 8. Shakhashiri, B. Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry; University of Wisconsin Press: Madison, WI, 1989; Vols. 1–4. 9. Summerlin, L. R.; Ealy, J. L., Jr. Chemical Demonstrations A Sourcebook for Teachers; American Chemical Society: Washington, DC, 1985. 10. Summerlin, L. R.; Borgford, C. L.; Ealy, J. B. Chemical Demonstrations A Sourcebook for Teachers; American Chemical Society: Washington, DC, 1987; Vol. 2. 11. Garrett, G. J. Chem. Educ. 2003, 80, 743. 12. Moore, J. W. J. Chem. Educ. 1999, 76, 1469. 13. Hatcher-Skeers, M.; Aragon, E. J. Chem. Educ. 2002, 79, 462– 464. 14. Exstrom, C. L.; Mosher, M. D. J. Chem. Educ. 2000, 77, 1295–1297. 15. Koehler, B. G.; Park, L. Y.; Kaplan, L. J. J. Chem. Educ. 1999, 76, 1505–1509. 16. Lee, N. E.; Schreiber, K. G. J. Chem. Educ. 1999, 76, 917– 918. 17. Swim, J. J. Chem. Educ. 1999, 76, 628–629. 18. Louters, L. L.; Huisman, R. D. J. Chem. Educ. 1999, 76, 196– 197.
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