ABSTRACT
At the very beginning of this book, chemistry was defi ned as the science of matter. Chapter 2 examined the nature of matter, largely at a macroscopic level and primarily through its physical properties. Today, the learning of chemistry is simplifi ed by taking advantage of what is known about matter at its most microscopic and fundamental level-atoms and molecules. Although atoms have been viewed so far in this book as simple, indivisible particles, they are in fact complicated bodies. Subtle differences in the arrangements and energies of electrons that make up most of the volume of atoms determine the chemical characteristics of the atoms. In particular, the electronic structures of atoms cause the periodic behavior of the elements, as described briefl y in Section 1.5 and summarized in the periodic table in Figure 1.4. This chapter addresses atomic theory and atomic structure in more detail to provide a basis for the understanding of chemistry.
