Editorial Cite This: J. Chem. Educ. 2018, 95, 187−188
pubs.acs.org/jchemeduc
“Hey, ProfessorSomething Is Wrong in the Book” Norbert J. Pienta* Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, United States ABSTRACT: Differences among textbooks, electronic books, and content material on the Internet often lead to student confusion. The ease of searching for factual information on the Internet makes it difficult for students and instructors to be “on the same page”, literally and figuratively. Some of the issues can be resolved by focusing more (or entirely) on conceptual understanding with little (or at least, less) focus on factual knowledge. KEYWORDS: General Public, First-Year Undergraduate/General, Textbooks/Reference Books
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student might want to argue that they should get credit for the homework or test question. The question could have asked for creation of the order simply based on the trends, but the student may have become confounded because the set of random values from the Internet seems to prove his or her point. Of course, a solution would be to ask questions that focus on conceptual understanding (i.e., the reason for the order rather than the order itself). At present, the community might not be ready to abandon the order question. In fact, the questions in textbooks suggest that this is the case, and some of my colleagues argue that asking the order based on periodic trends is a conceptual question. How often do these issues arise, and does it really matter? The general chemistry program at the University of Georgia has documented a sufficient number of them for me to believe that others are having similar experiences. So where do the data come from? Textbooks can be used as reference sources, but where do they get their data? (This is not a challenge or accusation of all the book authors out there, who have to deal with these questions AND satisfy adopters and their students.) Another example relates to electronegativity values. Some sleuthing leads to two primary literature sources for values, the work of Pauling1 and that of Sanderson.2−4 The maximum value for electronegativity is reported as 4.0 by both. However, the Sanderson values are typically higher for most elements. However, the dif ference between any two elements is very similar and consistent between both of those models. The value of electronegativity for hydrogen is reported at 2.2 and 2.6 by Pauling and Sanderson, respectively. That value was reported to me as “wrong” even though comparing values in context gives essentially the same answer independent of the two sets of data. The point of comparing electronegativities of two atoms that comprise a bond should point out that any two atoms can interact in a manner ranging from a nonpolar bond to a polar bond to a pair of ions. The electronegativity values provide a simple model to understand behavior. (For the simple model, two significant figures seem sufficient, although values up to four significant figures can be found online.) Again, this is not a call for debate of the various sources and models, but a caveat about what happens when these values are used and abused in introductory courses. Furthermore, studies that report data
odern technology and the Internet have revolutionized the availability of content and potential materials to be used in education and in all aspects of our lives. Your Editor has become very comfortable with the instant gratification that comes with searching for some fact or detail from the past that has become obscured or forgotten. For example, when was the last time that the University of Georgia won the national title in U.S. college football? (It was not 2018, although they came close. It was 1980.) But how has the chemical education community adjusted to and made use of this easy access to information? Students certainly take the access for granted and use the Internet extensively, often to a fault. It is easier to search for R, the gas constant, online than to remember it or to look in the book. Unfortunately, other students also believe that searching for answers to homework problems provides them with the same kind of advantage. Historically, at least in my professional career, textbooks served as both a source of knowledge but also as a reference for information. In spite of predictions of its demise at least two decades ago, the textbook has persisted, and electronic alternatives are just now being embraced (or at least considered). The days of open access and interactive, electronic books are here! As an undergraduate, your Editor used the text as the primary source of factual information. Learning and remembering facts might have been convenient and a better alternative than constantly looking up facts. Without the evidence-based research of the past 50 years, the pedagogies of the 1970s promoted this aspect of learning. Between then and now, emphasis has shifted to more conceptual knowledge. At some point, the chemical education community will have to decide what (if any) factual information a student should know, given the extent and accessibility of online resources. At this time of transition, some situations demonstrate the dilemma. In general chemistry, the discussion of periodicity touches a host of properties: atomic radii, ionization energies, electronegativities, and so forth. Let us consider atomic radii. One might want students to predict the order for three atoms based entirely on trends in atomic radii (i.e., across a row or down a group) AND to provide reasons for the answer. The text is a likely source of self-consistent values in a table or graphic. However, if a student searches the Internet for the numerical values, the small variation in the values from a number of different sources might lead to confusion. Also, the © 2018 American Chemical Society and Division of Chemical Education, Inc.
Published: February 13, 2018 187
DOI: 10.1021/acs.jchemed.8b00032 J. Chem. Educ. 2018, 95, 187−188
Journal of Chemical Education
Editorial
from some method used to determine electronegativities can certainly report the number of significant figure apropos to the methods used. Again, the point here concerns the models and values appropriate to an introductory course. Textbooks or e-books have differences in other aspects related to the information provided. For example, there appear to be two (or more) “schools of thought” on certain thermodynamic values. Because I have used calorimetry and other sources of thermodynamic data in my formative years, seeing values for heats of reactions in units of kJ or kcal was expected and appropriate. In some general chemistry texts, those heats of reaction are reported in units of kJ/mol (or kcal/ mol). To justify this, these books provide justification by defining “moles of reaction”. Doing so apparently allows all energy units to be in units of kJ/mol rather than some in units of just kJ. To me, “moles of reaction” is as or more difficult to explain then how one uses context to understand whether to use kJ versus kJ/mol. Try explaining “moles of reaction” for a reaction in which none of the stoichiometric coefficients are 1. Furthermore, perusal of the IUPAC Gold Book5 suggests to your Editor that “moles of reaction” does not fit the definition of mole. However, the issue is not about being right or wrong; it is about communicating the ideas to our students. I look forward to a time when students (and faculty) quit telling me that something is wrong in the book, because they all recognize and understand the model or idea to appreciate why it may be different. For some, that time is called retirement.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Norbert J. Pienta: 0000-0002-1197-6151 Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS. Norbert J. Pienta is Professor and Director of General Chemistry at the University of Georgia, where he teaches and conducts research and scholarship about the teaching and learning of chemistry, devising methods, instruments, and analytics to characterize student learning and increase student success. He currently also serves as the editor-in-chief for the Journal of Chemical Education.
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REFERENCES
(1) Pauling, L. The Nature of the Chemical Bond, 3rd ed.; Cornell University Press: Ithaca, NY, 1960; p 93. (2) Sanderson, R. T. Electronegativity and Bond Energy. J. Am. Chem. Soc. 1983, 105, 2259−2261. (3) Sanderson, R. T. Principles of Electronegativity Part I. General Nature. J. Chem. Educ. 1988, 65 (2), 112−118. (4) Sanderson, R. T. Principles of Electronegativity Part II. Applications. J. Chem. Educ. 1988, 65 (3), 227−231. (5) For a definition of mole in the IUPAC “Gold Book”, see https:// goldbook.iupac.org/html/M/M03980.html (accessed Jan 2018).
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DOI: 10.1021/acs.jchemed.8b00032 J. Chem. Educ. 2018, 95, 187−188
