An understanding of chemistry is necessary to all other sciences from astronomy to zoology. Chemistry is seen as a central discipline in science, required at various levels for undergraduate programs in, to name a few, physics, biology, biochemistry, family and nutritional science, engineering, physiotherapy and pharmacy. Most of the materials used by engineers and technologists are made by chemical reactions and we all experience chemical reactions continuously, whether it be in breathing or baking a cake, driving a car or listening to a battery driven minidisk player. Chemistry is concerned with all aspects of molecules, their physical and chemical properties, their composition and structure, their synthesis and use in the 21st century.