Preface
In 1977, chemists Theodore L. Brown and H. Eugene LeMay (joined in subsequent editions by Bruce Bursten and Julia Burdge) published a general chemistry textbook titled Chemistry: The Central Science. Since that time, the label the central science has become more and more associated with chemistry above all other sciences.
Why? Follow along, if you will. Science is grounded, first and foremost, in mathematics. Math is the language of science. Any study of true science must use math as an inescapable tool. The most fundamental science is physics, the study of matter and energy. (For the sake of argument, I include astronomy as part of physics.) Then we progress to the study of the description of matter and how that description can change—that’s chemistry.
At this point, however, several directions are possible. Do you want to study the chemistry of living things? That’s biology. The chemistry of the earth? That’s geology. The chemistry of how compounds work in our body? That’s pharmacology. The application of chemistry to better our lives? That’s engineering (chemical engineering, to be more specific, and we’ve just opened the door to the applied sciences). Granted, there are connections between more fundamental sciences and others—geophysics, astrobiology, and so forth—but a map of the sciences and their interconnections shows the most obvious branches after chemistry. This is why we consider chemistry the central science.
This concept is reinforced by the fact that many science majors require a course or two of chemistry as part of their curriculum (indeed, perhaps this is the reason you are using this textbook). Do you want to study biology? You’ll need some chemistry courses. Are you a geology major? You’ll need to know some chemistry. Many engineering disciplines, not just chemical engineering, require some background in chemistry as well. The reason that chemistry is required by so many other disciplines is that it is, to overuse the word, central.
Chemistry is not just central; it’s all around you. You participate in chemistry every day. This idea is one of the major themes in this book. Chemistry is all around you, and you practice it every day whether you know it or not. Throughout these chapters, I will attempt to convince you that you play with chemicals every day, perform chemistry every day, and depend on chemistry every day. This is what makes chemistry an integral part, and what should make chemistry an integral part, of the modern literate adult.
The goal of this textbook is not to make you an expert. True expertise in any field is a years-long endeavor. Here I will survey some of the basic topics of chemistry. This survey should give you enough knowledge to appreciate the impact of chemistry in everyday life and, if necessary, prepare you for additional instruction in chemistry.
The text starts with an introduction to chemistry. Some users might find this a throwaway chapter, but I urge you to look it over. Many people—even scientists—do not know what science really is, and we all can benefit if we learn what science is and, importantly, what science is not. Chemistry, like all sciences, is inherently quantitative, so Chapter 2 “Measurements” discusses measurements and the conventions for expressing them. Yes, chemistry has conventions and arbitrarily adopted, agreed-on standards against which everything is expressed. Students are sometimes dismayed to learn that a hard science like chemistry has arbitrary standards. But then, all fields have their arbitrary standards that experts in that field must master if they are to be considered “experts.” Chemistry, like other fields, is no different.
Chemistry is based on atoms, so that concept comes next—indeed, the goal of this book is to introduce “atoms first” because they are the primary building blocks of our universe, and one tactic in studying chemistry is to focus on atoms as soon as possible. The structure of atoms determines how they behave in chemistry, so the next chapter discusses the structure of atoms, especially their electrons. Atoms make molecules, another important topic in chemistry, and how atoms do that is the subject of the next chapter, chemical bonds. As it turns out, chemical bonds give molecules certain shapes, and because the shape of a molecule impacts its properties, there is a chapter that discusses molecular shapes.
Matter exists in three common phases, and those phases also have an impact on how atoms and molecules behave. Chapter 7 “Solids and Liquids” discusses the two condensed phases of matter, the solid and liquid phases. Then the text gets to an important part of chemistry, which is an introduction to how chemicals change—chemical reactions and how we depict them.
Quantities are important in chemistry, as in all sciences. Chapter 9 “Stoichiometry and the Mole” introduces how chemistry keeps track of amounts, a topic called stoichiometry. A very important unit, the mole, is also introduced here. With these last two important topics on the table, the book presents a bit more detail on how electrons are important in chemistry, using the concepts of oxidation and reduction and some of their more practical applications. A discussion of gases, the third common phase of matter, follows, and then there is a presentation of that combination of multiple substances that we call a solution.
Energy is also an important topic in chemistry, so now that atoms and molecules, chemical reactions, and stoichiometry have been introduced, there is a presentation of energy as a quantitative property. The remaining chapters discuss certain applied topics that are still fundamental to our understanding: acids and bases, chemical equilibrium, and nuclear chemistry. The text finishes with a quick introduction to organic chemistry, if only to whet the appetites of those who thirst to know more.
Throughout each chapter, I present two features that reinforce the theme of the textbook—that chemistry is all around you. The first is a feature titled, appropriately, “Chemistry Is Everywhere.” These features examine a topic of the chapter and demonstrate how this topic shows up in everyday life. In Chapter 1, “Chemistry Is Everywhere: In the Morning” focuses on the personal hygiene products that you may use every morning: toothpaste, soap, and shampoo, among others. These products are chemicals, aren’t they? Ever wonder about the chemical reactions that they undergo to give you clean and healthy teeth or shiny hair? I will explore some of these chemical reactions in future chapters. But this feature makes it clear that chemistry is, indeed, everywhere.
The other feature focuses on chemistry that you likely indulge in every day: eating and drinking. In the “Food and Drink App,” I discuss how the chemistry of the chapter applies to things that you eat and drink every day. Carbonated beverages depend on the behavior of gases, foods contain acids and bases, and we actually eat certain rocks. (Can you guess which rocks without looking ahead?) Cooking, eating, drinking, and metabolism—we are involved with all these chemical processes all the time. These two features allow us to see the things we interact with every day in a new light—as chemistry.
Each section starts with one or more Learning Objectives, which are the main points of the section. Key Takeaways, which review the main points, end each section. Each chapter is full of examples to illustrate the key points, and each example is followed by a similar Test Yourself exercise to see if a student understands the concept. Each section ends with its own set of paired exercises to practice the material from that section, and each chapter ends with Additional Exercises that are more challenging or require multiple steps or skills to answer.
The mathematical problems in this text have been treated in one of two ways: either as a conversion-factor problem or as a formula problem. It is generally recognized that consistency in problem solving is a positive pedagogical tool. Students and instructors may have different ways to work problems mathematically, and if it is mathematically consistent, the same answer will result. However, I have found it better to approach mathematical exercises in a consistent fashion, without (horrors!) cutesy shortcuts. Such shortcuts may be useful for one type of problem, but if students do not do a problem correctly, they are clueless as to why they went wrong. Having two basic mathematical approaches (converting and formulas) allows the text to focus on the logic of the approach, not the tricks of a shortcut.
Tabulations of unnecessary data, such as the densities of materials, are minimized for two reasons. First, they contribute nothing to understanding the concepts. Second, as an introductory textbook, this book focuses on the concepts and does not serve as a reference of data. There are other well-known sources of endless data should students need them.
WHAT’S NEW in the second edition: The entire manuscript has been re-evaluated and updated as necessary. Typographical errors have been corrected, and in a few places answers to exercises were slightly modified to accommodate for proper significant figures. Most importantly, the periodic table has been updated to include the completed seventh period, complete with IUPAC names and symbols.
Good luck, and good chemistry, to you all!
David W. Ball
December 2018