Chemical Education Today
Reports from Other Journals
The Science Teacher: Fall 2004 by Steve Long
Several articles published in The Science Teacher (TST) from January through May 2004 are summarized in this column. Their topics include gas laws, symbols in chemistry, inquiry techniques, models, biochemistry, and polymers. A variety of laboratory activities, teaching tips, models, and student-community projects are described. An error led John Stiles to a variation of the classic “mystery powders” lab activity in “I Lost the Answer Key”. Stiles states, “The day I lost my answer key to the Mystery Powders lab, students took charge of their learning and authentic science flourished in my classroom.” While conducting the mystery powders activity with preservice teachers, Stiles discovered his answer key to the unknown mystery power mixtures was missing. He describes the process the students used to collect, discuss, and verify their laboratory results. He summarizes it by saying that while the students were frustrated with the uncertainty of their findings, they gained insight into both the nature of scientific investigations and the influence of human error. “A Simple Experiment with Unknown Liquids” published in this Journal described a liquid version of a mystery lab using HCl, Na2CO3, phenolphthalein, and water (1). Readers could easily adapt this unknown liquid lab using the approach described by Stiles. “Chemistry as a Second Language” describes techniques to assist students, especially second-language learners, with mastering core chemistry concepts. Cara Hanes details her approaches to teaching chemical symbols, formulas, names, equations, and the mole concept by incorporating strategies that include multiple intelligences, the learning cycle, visuals, laboratory activities, small group work, and assessments. Hanes describes examples of learning strategy applications as she sequentially develops acquisition of both chemical terminology and concepts for students. While the article emphasizes second-language learner students, Hanes confirms “…these methods help all my students succeed in chemistry”. Peter Markow was encouraging JCE readers in 1988 about this same topic in “Teaching Chemistry Like the Foreign Language It Is” (2). He drew comparisons between general chemistry students and beginning foreign language students, and described how he started his general chemistry classes with the symbols and language of chemistry rather than the more traditional start with a review of mathematics or a discussion of matter. Marais and Jordaan ask, “Are We Taking Symbolic Language for Granted?” (3). The abstractions in chemistry make it a difficult subject to understand. The authors reported the results of their research on different groups of students. They concluded, “As chemistry teachers, we should therefore realize that students may have problems with the meanings of symbols and purposefully ‘teach’ symbolism to ensure that our students understand it as we do.” Marais and Jordaan offer four untested suggestions for teachers to try.
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A method for learning the symbols of elements is demonstrated in “Mixing Proverbs and Chemistry” by Rochelle T. Papasin, who uses the symbols of the elements to spell out popular proverbs for her students. Papasin believes, “The strategy effectively integrates chemistry with language and value-formation.” Six examples of these word puzzles are provided in the article. Jorge Ibanez also used proverbs in teaching chemistry in his JCE article (4). However, he connected proverbs with chemical phenomena. Ibanez provided 26 examples of using proverbs in chemistry that he believed would serve to introduce, reinforce, or clarify chemistry concepts. Kelkar described a different method of teaching chemical symbols using letter matrix puzzles (5, 6). The puzzles he designed offer an entertaining and useful way to assist students with learning symbols of elements. If readers desire to remember the symbols for the first 105 elements, Covey reported a mnemonic for this task (7). While the mnemonic is definitely a foreign language for me, readers may find it valuable. Using modeling clay as a tool to guide students through the macroscopic, particle, and symbolic levels of chemical understanding is the focus of “Models That Matter”. Students use colored modeling clay to form spheres representing atoms of elements. These spheres are used as manipulatives for forming compounds and representing chemical reactions. Authors Hitt and Townsend provide a sample activity following the 5E (engage, explore, explain, elaborate, evaluate) learning cycle. They state “The models engage students and stimulate on-topic conversations more than other approaches we have tried.” They also emphasize that the clay models are both affordable and accessible. “Learning How to Think” recounts an inquiry unit on gas laws focusing upon the explanation portion of the 5E learning cycle. In this laboratory-based lesson the authors develop Charles’s and Boyle’s laws as well as the Kelvin temperature scale. Students work in cooperative groups to investigate, gather data, look for patterns, graph data, and draw conclusions to construct their own conceptual understanding of the gas laws. The article includes suggested questions for developing the explanation phase of the learning cycle as well as sample student data. The authors provide leading questions that teachers can use to help direct the cooperative groups toward meaningful conclusions. John R. Peterson uses the model of gravel in a road intersection to explain the relative sense of energy in “An Island of Stability”. Peterson describes the gravel distribution in a roadbed corner as an analogy of the velocities and energies of particles. He also provides applications of his model to chemistry, physics, Earth systems, and astronomy. In chemistry, Peterson uses the gravel model to explain entropy and enthalpy in a chemical reaction as well as activation energy barriers.
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www.JCE.DivCHED.org
Chemical Education Today
Students study omega-3 fatty acids found in fast foods in “Nutritional Chemistry”. The ratios of omega-6 and omega-3 fatty acids in salmon, fish oil supplements, donuts, and fast food french fries were investigated using gas chromatography. Students developed the procedures necessary to successfully separate the two fatty acids with gas chromatography and determined the amounts present. Janice Crowley’s students presented their findings at a medical conference and to industry scientists as well as to their school. Crowley says the students positively affected their friends, family, and themselves about fatty acid nutrition with their research. They learned teamwork, leadership, problem solving, and lab techniques. Crowley and numerous co-authors published their initial research on the linoleic and linolenic fatty acids in french fries in a recent Journal issue (8). The May issue of TST emphasizes student–teacher–community success stories. Some of the articles include chemistry in an integrated context. “SAFEH2O”, by Ed Rhode, explains the not-for-profit water testing business his students provide for the local community. The students test drinking water samples for pH, hardness, lead, chlorine, copper, and for levels of bacteria. The students are starting a new project, WasHands, to develop a soap dispenser that promotes proper hand washing. “Polymers and People” is another success story. Teams of students taught their peers about polymers using a library exhibit, guest speaker, and lab activities. Starting with DNA, students learned about both natural and synthetic polymers. There are four lab activities in the article: constructing molecular models, making and testing nylon, creating and
evaluating bouncy balls, and an inquiry activity on the percentage of water for making the best gluep. A JCE Classroom Activity provides more information for both instructors and students on making and experimenting with gluep (9). A “Polymer Science Pilot Program” was explained in this Journal by Mary Maier (10). This program was a “…sequence of experiences with polymers, designed to focus upon the ways in which these materials resemble and/or compare with nonpolymers…”. Literature Cited 1. 2. 3. 4. 5. 6. 7. 8.
Sanchez, M. J. Chem. Educ. 1987, 64, 964. Markow, P. J. Chem. Educ. 1988, 65, 57–58. Marais, P., Jordaan, F. J. Chem. Educ. 2000, 77, 1355–1357. Ibanez, J. J. Chem. Educ. 2002, 79, 454–455. Kelkar, V. J. Chem. Educ. 2002, 79, 456–457. Kelkar, V. J. Chem. Educ. 2003, 80, 411–413. Covey, W. J. Chem. Educ. 1988, 65, 1089. Crowley, J.; DeBoise, K.; Marshall, M.; Shaffer, H.; Zafar, S.; Jones, K.; Palko, N., Mitsch, S.; Sutton, L.; Chang, M.; Fromer, I.; Kraft, J.; Meister, J.; Shah, A.; Tan, P.; Whitchurch, J. J. Chem. Educ. 2002, 79, 824–827. 9. JCE Editorial Staff. J. Chem. Educ. 1998, 75, 1432A– 1432B. 10. Maier, M. J. Chem. Educ. 1996, 73, 643.
Steve Long teaches at Rogers High School, Rogers, AR 72756;
[email protected].
Deming, John C.; Cracolice, Mark S. Learning How to Think. TST 2004, 71 (3) 42–47.
TST Featured Articles Stiles, John. I Lost the Answer Key. TST 2004, 71 (1), 31–33.
Peterson, John R. An Island of Stability. TST 2004, 71 (3) 54–56.
Hanes, Cara. Chemistry as a Second Language. TST 2004, 71 (2), 42–45.
Crowley, Janice. Nutritional Chemistry. TST 2004, 71 (4) 49–51.
Papasin, Rochelle T. Mixing Proverbs and Chemistry. TST 2004, 71 (2), 60–61.
Rhode, Ed. SAFEH2O. TST 2004, 71 (5) 28–29.
Hitt, Austin; Townsend, Jeffery Scott. Models That Matter. TST 2004, 71 (3), 29–31.
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Lentz, Linda; Robinson, Thomas; Martin, Elizabeth; Miller, Mary; Ashburn, Norma. Polymers and People. TST 2004, 71 (5) 30–31.
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