What is Chemistry ?
Chemistry is defined as the study of matter and its properties. Matter is defined as everything that has mass and occupies space. Although these definitions are acceptable, they do not explain why one needs to know chemistry. The answer to that query is that the world in which we live is a chemical world. Your own body is a complex chemical factory that uses chemical processes to change the food you eat and the air you breathe into bones, muscle, blood, and tissue and even into the energy that you use in your daily living. When illness prevents some part of these processes from functioning correctly, the doctor may prescribe as a medicine a chemical compound, either isolated from nature or prepared in a chemical laboratory by a chemist.

The world around us is also a vast chemical laboratory. The daily news is filled with reports of acid rain, toxic wastes, the risks associated with nuclear power plants, and the derailment of trains carrying substances such as vinyl chloride, sulfuric acid, and ammonia. Not all chemical news is of disasters. The daily news also carries stories (often in smaller headlines) of new drugs that cure old diseases; of fertilizers, insecticides, and herbicides designed by chemists to allow the farmers to feed our growing populations, and of other new products to make our lives more pleasant. The packages we buy at the grocery store list their contents, including what chemicals the package contains, such as preservatives, and the nutritional content in terms of vitamins, minerals, fats, carbohydrates, and proteins.

Everyday life is besieged with chemicals. In beginning the study of chemistry, it is unwise to start with topics as complex as the latest miracle drug. We will begin with the composition of matter and the different kinds of matter. We can then talk about the properties of the different types of matter and the changes that each can undergo. You will learn that each of these changes is accompanied by an energy change and learn the significance of these energy changes.