The Science Teacher: Winter 2003

seeing this as a student in seventh grade. However, as a teacher he questioned the explanation he had learned in “Seeing Isn't. Always Believing”...
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The Science Teacher: Winter 2003 by Steve Long

A favorite chemistry activity for many students and teachers is making slime. David L. Brock reports a new and improved slime created from a combination of both polyvinyl alcohol and white water-based glue using sodium tetraborate solution as the polymerizer. Brock states that the improved slime is sticky without leaving a residue, oozes but is easily removed, is soft and cold, and is easily stored for an extended time. Procedures for making this revised slime are provided in the article. Descriptions of the chemical processes behind both the polyvinyl alcohol slime (8) and the white glue, polyvinyl acetate slime (9) were previously published in this Journal. Also, a JCE Classroom Activity on making gluep, the white glue slime, contains suggested activities for using it with students (10). In “A Sweet Balance”, Lunsford and Strope explain how they use two activities on balancing chemical reactions to help students understand this fundamental chemical concept. The activities use hex nuts and sugar cookies as examples. Descriptions of the two procedures along with notes for the effective implementation of the activities are included. The authors’ study shows that using traditional teaching techniques, university students scored 38% on a pretest of balancing reactions and related concepts. They state, “However, students who participated in this balancing chemical reactions activity achieved a posttest score of 82% out of 100% after one year.” William C. Herndon published a critical review and an annotated bibliography on balancing chemical equations that readers may find useful (11). Ferguson provides a chemical equation that appears to have multiple coefficients for balancing the reaction by inspection (12). This reaction may stimulate students’ discussions and serve as an introduction to redox chemistry as a correct method of balancing the equation. “Minimizing Misconceptions” is a goal for all teachers: author Vicente Talanquer has attempted to provide “tools for identifying patterns of reasoning.” Talanquer presents a set of rules he has developed that seem to underlie most student

“Seeing Isn’t Always Believing” by Neil Glickstein (TST 2002, 69 (7), 41–43) “Probing for Understanding” by Thomas W. Shiland (TST 2002, 69 (7), 48–51) “Surveying Science Safety” by Jack A. Gerlovich and Rahul Parsa (TST 2002, 69 (7), 52–55) “Sticky Slime” by David L. Brock (TST 2002, 69 (7), 62) “A Sweet Balance” by Suzanne Lunsford and Cheri Strope (TST 2002, 69 (8), 42–45) “Minimizing Misconceptions” by Vicente Talanquer (TST 2002, 69 (8), 46–49)

JChemEd.chem.wisc.edu • Vol. 80 No. 2 February 2003 • Journal of Chemical Education

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TST Featured Articles

This report covers articles from The Science Teacher from May through November 2002. Because the May and September issues did not contain any chemistry-related articles, this review focuses upon the October and November issues. They contain articles related to safety, demonstrations, chemistry misconceptions, and activities. Many teachers have used the classic demonstration of burning a candle under a glass jar. Neil Glickstein recalled seeing this as a student in seventh grade. However, as a teacher he questioned the explanation he had learned in “Seeing Isn’t Always Believing”. Glickstein and his students used this candle demonstration as a research project to verify whether the popular explanation of air containing 20% oxygen (thereby causing water to rise in the jar by 20% volume after the candle burned) was accurate. They tested numerous variations on the classic demonstration, and they determined that the traditional explanation is incorrect. They plan to continue research on the project to better understand the process. Two articles in this Journal, “The Persistence of the Candle-and-Cylinder Misconception” (1) and “‘Experiment with a Candle’ without a Candle” (2), provide additional insights into this demonstration and an explanation of the event. Also, Peckham’s article, “A New Use for the Candle and Tumbler Myth”, explains how to turn this misconception into an enlightening activity (3). Thomas W. Shiland discusses examples of assessment probes (open-ended questions based upon everyday phenomena) to measure the depth of his students’ understanding. “Probing for Understanding” includes six chemistry examples of probes the author has used along with samples of students’ responses. The author believes, “Requiring students to explain and predict allows teachers to measure whether or not the material is understood.” Shiland describes the characteristics of effective probes and includes a short section on analyzing students’ responses. An editorial in this Journal has addressed the important connections among assessment, achievement, and understanding (4). The use of portfolios for assessment in high school chemistry (5) and a study of students’ and teachers’ conceptual understandings of gas laws (6) are two topics in recent Journal articles related to nontraditional assessment techniques. “Surveying Science Safety” is the summary report of a National Science Teachers Association membership Web-based study of safety issues. In the fall of 2000, 302 science teachers voluntarily answered a 33-question survey that included the topics of facilities, procedures, equipment, and concerns. The article tabulates the results with some discussion of the issues. A recent keyword search for “safety” in this Journal returned more than 600 records dating back to 1925. Included were numerous articles from the Safety Tips column edited by Tim Champion and the Chemical Laboratory Information Profile (CLIP) written by Jay A. Young. John W. Moore reminds readers that “Safety Pays” in a recent JCE editorial (7).

Chemical Education Today

Reports from Other Journals misconceptions in chemistry. The eight patterns of student reasoning are described along with examples of alternative conceptions. He states that the eight reasoning rules are not necessarily complete, but that the simplifications are useful teaching tools. Talanquer believes that, “By distinguishing clear patterns of reasoning, teachers can face the long list of student misconceptions without feeling overwhelmed.” Authors in this Journal have reported on their efforts to deal with student misconceptions. Examples include Bradley and Brand sharing “Stamping Out Misconceptions” (13), and Nakhleh discussing “Why Some Students Don’t Learn Chemistry” (14). Perhaps the reviewed articles or the referenced articles will provide you with an incentive to explore some of these topics more deeply. Literature Cited 1. Birk, J., Lawson, A. J. Chem. Educ. 1999, 76, 914–916. ˇ S. J. Chem. Educ. 2001, 78, 914. 2. Krnel, D., Glazar,

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3. Peckham, G. J. Chem. Educ. 1993, 70, 1008–1009. 4. Moore, J. W. J. Chem. Educ. 1997, 74, 477. 5. Phelps, A., LaPorte, M., Mahood, A. J. Chem. Educ. 1997, 74, 528–531. 6. Lin, H., Cheng, H., Lawrenz, F. J. Chem. Educ. 2000, 77, 235–238. 7. Moore, J. W. J. Chem. Educ. 2001, 78, 7. 8. McLaughlin, K., Wyffels, N., Jentz, A., Keenan, M. J. Chem. Educ. 1997, 74, 97–99. 9. Gilbert, R., Fellows, C., McDonald, J., Prescott, S. J. Chem. Educ. 2001, 78, 1370–1371. 10. JCE Editorial Staff J. Chem. Educ. 1998, 75, 1432A–1432B. 11. Herndon, W. J. Chem. Educ. 1997, 74, 1359–1362. 12. Ferguson, L. J. Chem. Educ. 1996, 73, 1129. 13. Bradley, J., Brand, M. J. Chem. Educ. 1985, 62, 318. 14. Nakhleh, M. J. Chem. Educ. 1992, 69, 191–196.

Steve Long teaches at Rogers High School, Rogers, AR 72756; [email protected].

Journal of Chemical Education • Vol. 80 No. 2 February 2003 • JChemEd.chem.wisc.edu