Julio Andrade-Gamboa
Área de Química, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Río Negro, Argentina
Most of the articles and textbooks that show drawings of enantiomorphous crystals use an inadequate view to appreciate the fact that they are non-superimposable mirror images of one another. If a graphical presentation of crystal chirality is not evident, the main attribute of crystal enantiomorphism can not be recognized by students. The classic case of tartaric acid crystals is discussed and the use of an alternative graphical representation and a paper model is proposed to facilitate the conceptualization of this subject.
Supplement
An enlarged version of the paper model shown in Figure 3 is available.
The "Chemistry Teacher Connection" (CTC) is especially for high school chemistry teachers. For only $40/year, it offers an online-only subscription to CLIC along with membership in the Division of Chemical Education, normally $65/year. CTC subscribers receive access to all articles and supplements from 1996 through the current issue.
Through special arrangement with the ACS, JCE High School CLIC is now able to provide subscribers with online access to Chemical & Engineering News articles that have been selected specifically for secondary science instructors and their students.
Occasionally, collections of JCE back issues become available for donation to individual teachers, schools, or libraries. JCE matches collections with interested recipients. Recipients pay shipping costs or pick up the collection.