# INTRODUCTION

There are difference forms of energy. all the energy cannot be used as a work. The convertibility of energy into work depends on its availability, how much energy can be converted into useful work. Thermodynamics is a branch of science and engineering that deals with interaction of energy mainly in the forms of heat and work. Thermodynamics is concerned with the thermal behavior of a matter and its interaction with other physical and chemical behavior of the matter. Broadly,  thermodynamics is studied into two forms-classical and statistical. Classical thermodynamics is concerned with the macrostructure of matter. It addresses the gross characteristics of large aggregations of molecules and not the behavior of individual molecules. The microstructure of matter is studied in kinetic theory and statistical mechanics. Statistical thermodynamics is concerned with the microstructure of the matter and address behavior of individual molecules of the matter.

MACROSCOPIC Vs MICROSCOPIC VIEWPOINT OF THERMODYNAMICS

Macroscopic and microscopic views are used to study the behavior of the matter . If the matter is studied about its behavior on the basis of certain amount or volume without consideration of its properties at the molecular level. It is known as macroscopic thermodynamics. If the matter is studied at its molecular level for its properties, it is known as microscopic thermodynamics. Both macroscopic and microscopic thermodynamics are discussed in the following section in detail.

MACROSCOPIC (Classical Thermodynamics)

1. In this approach, a certain quantity or volume of the matter is considered, without taking into account the events occurring at the molecular level.

2. This approach to the study of thermodynamics properties does not require knowledge of the behavior of individual particles.

3. It is only concerned with the effects of the action of many combined molecules, and these effects can be perceived by human senses.

4. The macroscopic observation are completely independent of the assumptions regarding  the nature of matter.

MICROSCOPIC (Statistical Thermodynamics)

1. From the microscopic viewpoint, it is assumed that matter is composed of a large number of small molecules and atoms.

2. This approach to the study of thermodynamics requires knowledge of the behavior of individual particles.

3. It is concerned with the effects of the action of many molecules, and these effects cannot be perceived by human senses.

4. The microscopic observation are completely dependent on the assumptions regarding the nature of matter.