Engineering chemistry can be described as the development that meets the necessities of the present without compromising the ability of future generations to satisfy their own needs. The idea and concept of Engineering chemistry can be interpreted in many ways, however, at core its an approach towards development that looks to balance different, and often competing, necessities against an awareness of the environmental, social and economic limitations we confront as a society. Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials into useful products. Atomic structure refers to the structure of atom comprising a nucleus (center) in which the protons (positively charged) and neutrons (neutral) are present. The negatively charged particles called electrons revolve around the center of the nucleus. Electrochemistry is the area of chemistry dealing with the interconversion of electrical energy and chemical energy. There are many applications of this in everyday life. Batteries, control of corrosion, metallurgy and electrolysis are just a few examples of the applications of electrochemistry. Polymers affect every day of our life. These materials have so many varied characteristics and applications that their usefulness can only be measured by our imagination. Polymers are the materials of past, present and future generations. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases. Engineering Chemistry is written exclusively for students of all branches of engineering, keeping in view their professional requirements.