BEHAVIOR OF SOLIDS

Compressibility.

FACT : It is even more difficult to compress solids that liquids.

THEORY : The particles that make up solids are in contact with one another. Any significant compression must result in the deforming of the individual particles.

 Diffusion.

FACT  :

THEORY  :

Evaporation and melting

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SOME PHYSICAL MEASUREMENTS

SOME PHYSICAL MEASUREMENTS

SOMEONE HAS SAID That the abiding impulse in every human being is to seek order and harmony. This search for order is clearly visible in our study of nature. We see that many objects are rigid, but that others flow easily and do not have definite shapes. We want to distinguish these types and we even give them names-solids and liquids. When we try to describe substances such us tar, butter, and glass, which do not fit well into either the solid or the liquid class, we may be somewhat confused. We many decide arbitrarily to put them into one class or the other, or we may think of another class or a new subclass.

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PREFACE

Question :   Why should a student take a course in general chemistry ?

Answer   :   Because it teaches him to think, to reason, and to imagine.

This answer, given by Professor William McPherson during a discussion at an American Chemical Society meeting in 1922, is as valid today as it was then. Since that time chemistry has come to influence our lives so directly and to reveal nature so beautifully that many people feel that any educated person should have some acquaintance with chemistry and its methods.

The very breadth of the subject, however, imposes difficulties. Teachers of beginning college chemistry courses have recognized the necessity of limiting the amount of material presented in a first-year course. But there has been little agreement as to precisely what this course should include. This is as it should be, for the abilities of student very widely, as do their interests and objectives. 

Nevertheless, most teachers do agree that as chemistry or any subject, for that matter-Develops, material which becomes dated must be replaced by material that is timely and fresh. In this repLacement process there is understandable resistance to discarding subject matter which has for years been accepted as an important feature of the discipline.

Frequently, therefore, rather than discarding it we retain it, using it as a historical introduction to the new material. But in keeping all thet is good of the old and squeezing in all that we can of the new, we risk inflating the content of the course so unreasonably that for the student it represents drudgery rather than inspiration.

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