Ebook: Basic Physics of Atoms and Molecules

From the preface:
"We feel that quantum physics no more abstract than Newtonian mechanics, but it took a long time before Newtonian mechanics appeared as plausible as it does today. This book attempts to make quantum physics a little more plausible to a few more people.
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This book is directed primarily to research workers in the natural sciences and presupposes, therefore, only a general knowledge of physics and mathematics. We have tried to develop ideas and establish laws through inductive analysis of experiments and only then to formulate the mathematical symbols, equations, and calculations that represent them. Since mathematics is a shorthand language, the preliminary reasoning in English is a costly proposition. As starting points for the inductive analysis we have chosen a few experiments that appear to illustrate most directly the characteristic properties of atomic systems. Some of these experiments are not accurate or easy to perform and therefore did not play a significant role in the historical development of quantum physics. That is, the experiments have been chosen for their pedagogical value; the conclusive evidence of quantum theory comes from its agreement with all the results of a vast array of accurate experiments.
This book intends to give a qualitative picture of the properties of atoms rather than to teach how to calculate the solutions of quantum mechanical problems."