Chemical Education Today
Reports from Other Journals
The Best of Chem 13 News by Kathy Thorsen
This column is designed to give JCE readers a few highlights from Chem 13 News, a monthly publication for chemistry educators from the University of Waterloo in Ontario, Canada. Before we know it, the leaves will be turning, and school will resume with a new group of students eagerly awaiting their chemistry class. This is the time of year when I search for new ideas to get “fired up” about returning to school. Thus, I would like to share a synopsis of articles from the October 1998 through February 1999 issues. Each of the following annotations describes a particular activity or a variety of sources from which new and creative ideas can be extracted. Daily Demos Engage Students Why did we become educators of science versus English, math, or history? We hope that the decision stemmed from an interest in understanding our natural world and passing on to others our curiosity and love for science. Perhaps the underlying motive is that science educators simply have more fun. Just about any topic presented in a chemistry class can be enhanced by a demonstration. Where can we, as chemistry teachers, find enough ideas and tested procedures to incorporate a daily demonstration into our lectures? The October 1998–January 1999 issues of Chem 13 News provide a comprehensive list of resources no chemistry teacher should be without. Three separate parts, spread over the four issues, complete a series that presents chemical demonstration resources from books, journal articles, and the Internet. Jeannine E. Eddleton, Gary L. Long, and Larry T. Taylor have searched a number of sources as mentioned in the introduction to each section of the paper. For the sections involving printed material (parts 1 and 2), the authors have updated the bibliography of lecture demonstrations by David Katz— “Science Demonstrations, Experiments and Resources: A Reference List for Elementary through College Teachers Emphasizing Chemistry with Some Physics and Life Science”— published in 1991 by the Journal of Chemical Education. Part 1 in the October and November 1998 issues (p 16 and 10, respectively) lists the author, title, publisher, and detailed descriptions for books that are in and out of print. Some of the titles include Twenty Demonstrations Guaranteed to Knock Your Socks Off! by Robert Becker, Chemical Magic from the Grocery Store by Andy Sae, and Lessons in Chocolate by Ginger Tannenbaum. “Part 2, Journal Articles” can be found in the December 1998 issue (p10). The authors directed their search toward demonstrations that are not commonly found in texts or in journals other than the Journal of Chemical Education— some of which are not easily accessible in the United States. The individual journal articles are listed in separate categories that are common to most general chemistry curricula. The last part of the series, “The Internet as a Resource”, is published in the January 1999 issue (p 12). Due to the 884
rapidly changing nature of the Internet, the authors warn that the Web sites presented are only a partial list and only cover materials available through January 1997. (Anyone unfamiliar with the Internet should note that Web site addresses change frequently to make room for new sites). The purpose of this section was to provide the reader with a sense of the myriad instructional media on the Internet (from Web sites, newsgroups, and listservers). However, the authors caution that the Internet may not be the most efficient and accurate resource at this time, considering the lack of supervision. Throughout the paper, the authors incorporate comments on the scientific reliability of the source as well as safety issues where necessary. They discovered in their search that many demonstrations were duplicates of previous publications with slight variations on the methodology. Overall, the authors stress the importance of using these sources to find supplemental material to enhance our students’ understanding of concepts presented in lectures and textbooks. Missed the Big Event? Never Fear, Abstracts Are Here As an educator, our “free time” is gobbled up by meetings, assessing students’ work, extra duties, and activities, to name a few. The idea of traveling to a convention or professional meeting, though tempting and definitely worthwhile, is often brushed aside due to other priorities or lack of travel funds. However, if you subscribe to Chem 13 News, the conventions, meetings, and other events come to you through abstracts of selected presentations. Reports from the 15th Biennial Conference on Chemical Education and the American Chemical Society Meeting appear in the January and February 1999 issues, respectively. Andy Cherkas from Stouffville District Secondary School reports on a few favorite BCCE presentations (p 5). Several demonstrations and uses of materials purchased from the grocery store are described in the abstract “Supermarket: Super Chemistry”. “Instructive and Entertaining Chemical Demonstrations”, presented by Irwin Talesnick, offers some ideas in using demonstrations to provoke students to think. Several abstracts from the August 1998 ACS meeting (p 10) provide insight to some interesting topics, such as the “History and Discovery of Element 61” and using feather protein as a biopolymer. Another abstract presents a series of experiments on popcorn that can be used to derive linear relationships. Most abstracts include the presenter’s name and address if the reader wants more information about a particular presentation. Hot or Cold? Density Is as Simple as That On the front page of the November 1998 issue of Chem 13 News, Jeffrey Bracken describes a creative demonstration to show the effect of temperature on water density. The beauty of the demo stems not only from the layers of water that are
Journal of Chemical Education • Vol. 76 No. 7 July 1999 • JChemEd.chem.wisc.edu
Chemical Education Today
distinguished by color but also from the simplicity of the procedure and required materials: vinyl tubing, two racquetballs, a funnel, and a light source. The only advanced preparation needed is to cut a 5.0cm slot along the top of the tubing. A clear diagram and a complete description of the procedure are included. The entire demonstration can be conducted in front of the class. A student assistant holding the tube in the folded position, as the teacher pours the liquid, would add to the presentation. I would advise conducting the procedure over the sink or garbage can in case the tube or racquetballs slip. Large rubber stoppers also work well at the ends of the tube. The two layers of colors are readily visible if the tube is placed in front of a light source, such as a window or a lightbox. A Money Exchange for Reviewing Significant Figures The correct use of significant figures seems to be a mystery for many beginning as well as advanced chemistry students. Glen Loveridge proposes an introductory lab to review units and significant figures with second-year students. The procedure described in the November 1998 issue (p 4) uses Canadian currency, but it can be adapted using any paper-based bills. The students calculate the thickness of one sheet of bills using the density of Canadian paper currency; the author gives a value of 0.82 g/cm3. But for students doing the activity in the U.S., they should use the density of U.S. paper currency, which is approximately 1.1 g/cm3. In the second part of the activity, students will calculate the mass of a plastic bill, using transparency sheets to represent the new bills being used in Australia. The author provides an organized handout to use or adapt for the activity. He makes a point of having the students measure to the hundredths place and provides density values with only two significant digits to make the students think before recording their final answer. Demonstrations Are a Gas Carbon dioxide and liquid nitrogen have been the basis for many demonstrations in the chemistry classroom. Two articles, “Liquid Nitrogen Fountains” in the January 1999 issue (p 17) and “Improvements on the Leaky Faucet Demo” in the February 1999 issue (p 8), provide insight on new and improved methods for conducting experiments with these gases. The first demonstration involves the use of a clear tennis-ball container, filled with liquid nitrogen and 0.25-inch tubing of various polymer and metal materials. As streams of liquid nitrogen and “steam” shoot out of the tubes, the relationship between heat capacity and the rate that liquid nitrogen will vaporize can be compared. The author conducted a study on the height and timing of the streams of liquid nitrogen that emanate from each tube. The article in-
cludes a table summarizing the results as they relate to tube dimension and type of material. The second article provides diagrams and directions for improving the CO 2 leaky faucet demonstration. For those unfamiliar with the demonstration, soap bubbles filled with CO2 are produced from PVC piping, eight feet or more above the floor. As the soap bubbles fall, such principles as the density of gases and the condensation of water can be discussed. Basic improvements made to the original apparatus include cutting the 60-inch vertical tube and holder for the plastic cup in half and adding a union coupling to eliminate storage problems. A side arm flask replaces the original 2-L soda bottle with a stopcock inserted in the main rubber stopper. The side arm of the flask is connected to the PVC tube with flexible tubing. The author also suggests inserting an optional inlet into the flexible tubing to mix the CO2 with other gases, such as methane or propane. Operation of the apparatus is described as well as an alternative demonstration involving the ignition of pure propane bubbles. Tantalizing Tidbits about the Internet As the Internet grows, so does my address book of useful Web sites. In each issue of Chem 13 News, Ed Doadt introduces a new Web site in his column “Chemistry on the Internet: Untangling the Web”. I have picked out several “must see” Web sites that I have found particularly interesting. The October 1998 issue describes a fundamental site for chemistry educators, “The Catalyst” (http://www. TheCatalyst.org). If you are a first-time Internet user, this site is well-organized and provides a number of links to other reliable sites, as well as a bulletin board where users post questions and exchange ideas. Though many schools are updating their technology, not every classroom has a computer. Does this mean we have to wait for the referendum to pass in order to bring the Internet into our classroom? Ed Doadt describes a program called “WebWhacker” in the December 1998 issue (p 3) that can bring a Web site into your classroom without a live connection to the Internet. The program downloads all of the files and graphics linked to the Web site; so you can display it on any computer. Since the amount of information copied can be quite large, I would suggest using a large storage capacity disk to store the site’s files. The Internet can be used as an interesting resource tool, especially when a periodic table is needed. “The Comic Book Periodic Table” (http://www.uky.edu/~holler/periodic/ periodic.html) is described in the January 1999 issue (p 3). This table displays a color image for each element on the table. The site is user-friendly, contains several useful links, and entertains both the young and old. Kathy Thorsen teaches at Menomonee Falls High School, N84W16579 Menomonee Ave., Menomonee Falls, WI 53051;
[email protected].
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