The Historical Development of Modern Atomic Theory

Just as the atom is the building block from which all materials are made, this chapter must be the building block upon which the rest of the book is made. The remaining chapters of this book are devoted to topics directly related to the behavior that can only be understood by first learning atomic structure. The information in this chapter will provide you with a solid foundation of knowledge upon which to build the remainder of your review. The AP test has a few multiple-choice questions on the topics covered in this chapter and will periodically have one essay question as well. You will have a much easier time on the other sections of this book and the AP test if you can develop a firm understanding of atomic structure and its impact. 

The earliest known descriptions of atoms date back to between 460 and 370 B.C.E., when the Greek philosopher Democritus first proposed the idea that matter was composed of indivisible particles. He used the term atomos (indivisible) to describe these. Other philosophers, including Plato and Aristotle, opposed Democritus s ideas, believing that matter was infinitely 

During the period between 1803 and 1807, John Dalton proposed a theory of the atomic nature of matter. Dalton s four basic postulates stated the following  

Q All matter is composed of extremely small particles called atoms. 

0 Atoms are neither created nor destroyed in chemical reactions, nor do they change forms. 

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