Reviewing a high-school book in chemistry

Chemistry: Concepts and Applications
1997. 857 pages. ISBN of the student's edition: 0-02-827452-0.
Glencoe/McGraw-Hill, 936 Eastwind Drive, Westerville, Ohio 43081.
(Glencoe/McGraw-Hill is a division of the McGraw-Hill Companies.)

This Pleasant but Odd Book
Shows Too Many Omissions

Ronald P. Drucker

Would that display get you interested if you were fifteen years old again? Of course it would. Chemistry: Concepts and Applications excels in hooking the reader with engaging visuals and upbeat, readable prose.

The book's 21 chapters cover the usual array of topics: the nature of matter and the formation of chemical compounds; chemical reactions and equations; atomic structure and the periodic properties of the elements; bonding; the kinetic theory of matter; the gas laws; stoichiometry; solutions; acids and bases; redox reactions and electrochemistry; organic chemistry; biochemistry; and nuclear chemistry. Each chapter ends with a review that includes questions and writing assignments.

Was this book written for any defined audience? You cannot tell from the promotional material that Glencoe gives to teachers, since Glencoe paints Chemistry: Concepts and Applications as a book for everyone everywhere. After promising an "approach that increases every student's chance for success," the company claims that

This innovative chemistry program helps all your students succeed, wherever their career paths take them. Whether they're tech-prep students or college-bound, Chemistry: Concepts and Applications' real-world focus gives them the tools that ensure comprehension and mastery of essential chemistry concepts.

Let us keep the question of audience in mind as we sample some chapters and see how Chemistry: Concepts and Applications covers its subject.

Information about atomic structure is introduced early, in chapter 2. The writers make this material accessible through the use of lively writing and engaging illustrations, but some of their science is shaky. They mix sound waves and ocean waves into their section titled "The Electromagnetic Spectrum," and they state that "Electromagnetic waves have the same characteristics as other waves." Well, tell that to Michelson and Morley. Unlike sound waves and water waves, electromagnetic waves can propagate without a medium -- and Glencoe's writers acknowledge this fact by remarking that "electromagnetic waves can travel through empty space" (page 70). If that is true, how can electromagnetic waves have "the same characteristics" as waves in the ocean?

Later in the same chapter, the writers broach the idea of quantized energy levels in the Bohr model, but they generate confusion by using the phrase "energy level" to denote two different things: an electron's energy and the electron's position in space (page 75).

The idea of "energy level" is clarified in chapter 7, where the writers describe atomic orbitals and emphasize that the actual path of an electron is not a fixed orbit -- but shaky science intrudes again as the writers try to tell about the Heisenberg uncertainty principle. "In the 1920s," they say, "Werner Heisenberg reached the conclusion that it's impossible to measure accurately both the position and energy of an electron at the same time." What they mean is position and momentum. (Beyond that, I find it puzzling that they mention Heisenberg but ignore Schrödinger. Schrödinger merits a place in any discussion of orbitals, because he was the one who showed how to calculate orbitals and their energies.) Once the writers get rolling in their actual description of orbitals, though, they provide a clear account. I particularly favor the illustration which shows the overall spherical shape of an atom that has several filled orbitals.

One of this textbook's strengths is the recurrence, in various contexts, of the idea that microscopic structure determines macroscopic properties. But I disagree with the writers' attempt to explain the dipole-dipole forces in water by comparing the water molecules to "little bar magnets" (page 438). This analogy might have been acceptable if the writers had explained clearly that electric dipoles and magnetic dipoles are different things, but this point is not even mentioned. As a result, it is all too likely that students will acquire the idea that water is held together by magnetism.

In the chapters about acids and bases, the general properties of acids and bases are described clearly (with salutary distinctions between macroscopic and microscopic properties), and acid-base reactions receive systematic treatment. Yet here again there are some puzzling aberrations. On page 493, for example, a diagram purports to demonstrate the hydrolysis of a base by showing how the weak base ammonia reacts with water to produce ammonium and hydroxyl ions. But there is only one reaction arrow, pointing to the right, and the accompanying text says: "The hydrogen bond that forms between the N end of NH₃ and the H end of H₂O is strong enough to pull an H⁺ completely away from H₂O." This suggests, incorrectly, that ammonia is a strong base. And the gratuitous reference to hydrogen bonding will probably lead the student to believe, incorrectly, that hydrogen bonding must alway lead to ionization.

Skimpy Treatment

A surprising feature of this book is that the early chapters are free of SI units and free of exercises that teach the use of conversion factors. If an instructor were to teach the chapters in order, starting in September, the students would not tackle any meaningful numerical problems until February. The first such problems appear in chapter 11 -- half-way through the book -- which is titled "Behavior of Gases." Here the writers suddenly declare that "The SI unit for measuring pressure is the pascal (Pa), named after the French physicist Blaise Pascal (1623-1662)." But what does "SI unit" mean? The students haven't seen any explanation of SI units, and in fact they will never see such an explanation unless they study an appendix at the back of the book. Many students, who don't know an appendix from a tonsil, won't do this. By banishing the subject of SI units to an appendix, the writers have made a serious mistake. And they have made another, similar mistake by relegating to the same appendix their only discussions of scientific notation and of significant figures.

After springing the term "SI unit," the writers present a sample calculation showing how to convert 760 mm of Hg to inches of Hg. That is a reasonable opener. But it is immediately followed by problems that plunge the students into conversions dealing with kilopascals and pounds per square inch. How can students learn to solve gas-law problems while, at the same time, they are just beginning to learn to convert units?

When the writers turn to the gas laws, they adopt an odd approach: They eschew the use of formulas in problems involving Boyle's law or Charles's law, and they expect students to derive correction ratios from intuition about direct and inverse proportions. I object to this. Intuitive methods are important, but using formulas would make things clearer -- and it is entirely reasonable to expect high-school juniors or seniors to handle the relevant algebraic expressions.

The chapter about gases is followed by a single chapter on stoichiometry ("Chemical Quantities"). Here the coverage is admirably clear, and there's a reasonably thorough array of numerical problems (on pages 431 through 433). After that, quantitative chemistry receives little attention. The chapter about water and aqueous solutions has only seven quantitative problems. The chapter about acid-base reactions has only ten. The chapter about thermochemistry has only six. And the chapter on nuclear chemistry has only two! These chapters offer plenty of other study-questions, many of which are good, but students and their instructors will find few opportunities to work with numbers.

Let me now return to my question about the book's audience. Chemistry: Concepts and Applications, with its thin treatment of quantitative matters, has obviously been written for students who are weak in math. Such students may find the book comforting. But they certainly will not be pushed to extend their mathematical skills, and they will be denied their right to learn many of the concepts that all students should master during a high-school chemistry course. I feel strongly that students should not be written off in this way, even if they are less able than some of their peers. I would urge Glencoe's writers, when they work on the next edition, to match this book's fine descriptive prose and effective illustrations with good quantitative material, including adequate sets of numerical problems.

"Virtual Lab Experiments"?

PROVIDE A COMPLETE CHEMISTRY LAB EXPERIENCE . . . WITHOUT CHEMICALS . . . Your students will have all the adventure of a full laboratory experience without environmental or safety concerns. . . . You can conduct virtual lab experiments without using a gram of actual chemicals.

After reading this, I had to spend several minutes in a virtual lotus position (safer and more practical than the real thing) to bring my heartbeat back to normal. Activities that exclude chemicals but provide a "full laboratory experience"? I believe that we have an Issue here, with a capital I.

Translated from the current version of Newspeak, Glencoe's phrase "virtual lab experiments" means simulations -- and there is no doubt that simulations can be helpful to students. If Glencoe had promised that CD-ROM simulations would enhance the information and the real laboratory activities presented in the textbook, I'd be applauding now. But it looks as if this company is trying to entice teachers who lack adequate laboratory facilities (or who lack the will to use them) by promoting the notion that video images constitute an equivalent alternative to hands-on laboratory work.

We should remember that the practice of including laboratory work in science courses was pioneered in the United States, in the early part of this century, under the leadership of such notable figures as the chemist Joel Hildebrand and the physicist Robert A. Millikan. As this innovation took hold (in undergraduate college courses, then in high-school courses, and eventually in the lower grades), traditionalists here and overseas wondered why valuable materials and instruments should be put into the hands of neophytes who might just as well learn from books alone. Now, of course, we regard laboratory work -- with all its messiness, but with its demonstrated power to engage and stimulate students -- as an integral part of all our high-school science. We must be very wary of abandoning it in favor of an all-electronic alternative.

This Weak, Silly Book
Is Suitable for No One

Max G. Rodel

Chemistry: Concepts and Applications has no preface or foreword, or anything else that might contain a clue to the book's purpose or intended audience. Glencoe's catalogue doesn't help, for it offers only some vague, catch-all claims: "This innovative chemistry program," the catalogue asserts, "helps all your students succeed, wherever their career paths take them. Whether they're tech-prep students or college bound, Chemistry: Concepts and Applications' real-world focus gives them the tools that ensure comprehension and mastery of essential chemistry concepts."

I cannot agree. This book surely is not suitable for high-school students who really want to learn chemistry or who want to major in science when they go to college. Rather, Chemistry: Concepts and Applications seems to be directed at vocational-ed students and slow learners -- and even for those audiences, it would only be marginally useful. Indeed, it is so shallow that it should be offered as a chemistry-appreciation book, not a chemistry text. The writers have concentrated on telling stories that relate chemistry to everyday life, and they have succeeded fairly well in that endeavor, but they haven't done much to teach real science.

So Chemistry: Concepts and Applications appears to be a product for poor students who need to complete a "science" requirement. This helps to explain the book's flashy appearance, but it doesn't justify the book's many inadequacies of content. Look, for example, at the cursory passage about the balancing of chemical equations, a topic that is vital to all introductory instruction in chemistry. Glencoe's writers seem to be thinking: These dummies won't understand it anyway, so we don't have to make a big deal of it.

The ad in Glencoe's catalogue boasts of "just the right emphasis on the quantitative aspects of chemistry." In practice, this seems to mean writing descriptive material for arithmetic-only students, avoiding even the simplest algebra. Chemistry: Concepts and Applications has less math in it than any genuine chemistry book has, and the writers don't even try to explain pH in any meaningful way. They simply define pH (on page 502) as "a mathematical scale in which the concentration of hydronium ions in a solution is expressed as a number from 0 to 14." That may be a suitable definition to recite to members of Congress, but not to students who are supposed to be learning chemistry.

Chemistry: Concepts and Applications is further weakened by many items which are false, misleading or obscure. For example:

• Page 10 shows ball-and-stick molecular models of aspirin and sucrose -- long before the student will encounter the concepts of elements, compounds, and chemical bonding. The writers themselves appear to be embarrassed by this, because they say (in the caption near the ball-and-stick figures): "Don't worry about not understanding the complete meaning of these structures." That is appropriate advice, because students will not have any idea of what they are looking at.

• Page 25: The "MiniLab" on this page deals with inducing the formation of a zinc-copper alloy on the surface of a penny -- but the introduction is a gratuitous passage about alchemy! The writers tell that the alchemists weren't chemists and that they failed in their attempts to transmute common metals into gold. What does any of that have to do with making an alloy?

• Page 55: Long before the writers develop the concept of a chemical reaction, they expect the student to understand a diagram of the nitrogen cycle.

• Page 131: Here we find the goofy headline "Noble Chemical Stability" and some text that is even goofier. Glencoe's writers say that the noble gases "used to be called the inert gases," and that the term "noble gases" wasn't coined until the 1960s. In fact, the word noble was used long before then, both in alchemy and in chemistry, to designate substances which are reluctant to enter into reactions under ordinary conditions. Further, the terms "noble gases" and "inert gases" aren't synonymous: The inert gases include many -- such as N₂ -- that aren't noble.

• On page 143 a caption states: "Potassium chloride (KCl) is used as a salt substitute because it has a taste similar to that of salt." Yes, but why would anyone want a "salt substitute" to begin with? If one wants something that tastes like salt, why not use salt? Not until later in the book will the writers remember to mention that some people must restrict their intake of sodium, for medical reasons, and that potassium chloride is a serviceable substitute for sodium chloride.

• Page 154: The notion that seawater contains compounds, such as sodium chloride or magnesium chloride, is nonsense. Dissociated sodium ions, magnesium ions and potassium ions are present in seawater, but the compounds are not.

• On page 575 a caption says that "it is common to think that only mammals keep warm." Huh?

Then there is the excessive use of gimmicky illustrations. Looking again at the Glencoe catalogue, I see the claim that "Captivating visuals are a powerful learning tool to aid students' memory and comprehension" -- but many of the illustrations in Chemistry: Concepts and Applications seem merely to be taking up space. As examples:

• Pages 28 and 29: Here the student gets his first view of the periodic table -- but it is a "Pictorial Periodic Table" in which each element is represented only by its symbol (without its name), its atomic number and atomic mass (which appear as unexplained, meaningless numbers) and a tiny illustration representing a "sample" of the element in question. (In eight cases, the "sample" is a compressed-gas bottle.) It is all so silly that the caption actually cautions the student not to rely on it. When the student needs a periodic table "for reference," the caption says, he should use the one that will appear later in the book. So why was this "pictorial" table printed to begin with?

• Page 537: In an article titled "The Development of Artificial Blood," the illustration shows two spheres and some twisted tubes. There is no explanation of this picture, and the caption simply says: "Artificial hemoglobin." (Not until page 672 will the student learn that twisted tubes are supposed to represent the 3-dimensional structure of a protein.)

• In fact, this schoolbook is truly rich in mysterious illustrations. On page 283, figure 8.11 shows a mercury barometer and a set of unidentified round objects. I have no idea what is supposedly being depicted here. Page 478 has a full-page photo of a bedraggled leaf -- but there is no caption, and the text on the facing page doesn't refer to the photo at all. Page 742 shows a big photo of a jewel-encrusted headdress, along with a little painting of a stereotypical alchemist. On the facing page, a paragraph mentions only "a Chinese alchemist named Shaajun" (though the alchemist on page 742 is obviously not Chinese), and it doesn't say anything about the headdress. Page 549 has an uncaptioned photograph of a woman who is carrying some bread and a bouquet, and who evidently is clutching her hat against the wind. What is this enigmatic photo supposed to show? Are Glencoe's illustrators trying deliberately to confuse the student?

Speaking of confusion: The "Metabolic Map" shown on pages 695 takes confusion to its limit. If the writers were seeking to bewilder and overwhelm their young readers, they have succeeded here.

One of the few things that this book does well is to touch all the bases of political correctness. The photographs seem to show at least one representative of every known "minority" group, or at least every group that has attained beatification in PC circles. There are the usual, trite distortions involving women, too. (On page 762, for example, the account of the discovery of nuclear fission is accompanied by an illustrated item about Lise Meitner, but there is no such item about Otto Hahn.) And I laughed aloud at one of Glencoe's hire-the-handicapped efforts, on page 240. Here we see a photo of the actor LeVar Burton in his role as Geordi, the blind character in the television series Star Trek: The Next Generation, while the accompanying text asks the student to divine whether Geordi's virtual-vision visor "will be available for the visually impaired [sic] in a few years?" Please, Glencoe! Baseless speculations about Geordi and his fantastic wonder-visor have nothing to do with helping anyone to learn about chemistry.

And of course, Chemistry: Concepts and Applications makes an obligatory, politically correct digression into preserving the rain forests. A whole page is devoted to a fluffy article titled "The Rain Forest Pharmacy," complete with vague intimations that rain forests are vast storehouses of valuable, pharmacologically active substances. There is even a meaningless photo of an unidentified native of some unidentified tropical land, holding an unidentified object that looks like a stalk of bamboo. Please spare us, Glencoe! The conservation of rain forests is a commendable and important mission, but your article is just inane.

[Editor's note: If teachers would like to read a sober, empirical assessment of rain forests as sources of pharmaceutical materials, they can find one in the NCAHF Newsletter, September-October 1996. The Newsletter is published by the National Council Against Health Fraud.]

Regular readers of The Textbook Letter know that I like to write a narrative analysis of each book that I review, rather than merely listing the book's defects and failings. Glencoe's book, however, is so bad that it has forced me to depart from my usual approach. Glencoe may believe that there are students who are so dumb that they cannot learn real chemistry, but I do not. In my view, Chemistry: Concepts and Applications is a book suitable for no one, and I cannot recommend it.

Ronald P. Drucker is a physical chemist. He teaches general and analytical chemistry at City College of San Francisco, and he is a co-director of that institution's Science Scholars program, which encourages members of racial minorities to pursue biomedical careers. He also represents City College in a collaborative that seeks to improve the education of math teachers and science teachers. The collaborative is supported by the National Science Foundation.

Max Rodel is a consulting environmental chemist and a registered environmental assessor in state of California. His major professional interest is the chemistry of natural aquatic systems, including the fates of pollutants. He lives and works in Mill Valley, and he regularly reviews science textbooks for The Textbook Letter.

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