Clausius wrote about вЂthe kind of motion we call heatвЂ™, but thermodynamics - either practical or theoretical - does not rely for its validity on the notion of molecules jumping around.' (E.H. No one has ever seen heat, nor will it ever be seen, smelled or touched. Neither can it explain what energy is, or temperature, chemical potential, or heat for that matter. It never will be able to explain what it is, however much symbol manipulation you do.

A вЂmeasure of unavailable energyвЂ™.Д®ntropy level higher in Gas: Solid< Liquid< Gas.You started out by stating that thermodynamics cannot explain what entropy is, which is correct, but then again nobody ever claimed it could. In other words, if you drop a box of matches on the floor, the matches will fall all over the place, which is an increase in entropy.Д®ntropy is a вЂmeasure of disorderвЂ™ of a system. Thus increase in entropy implies a transition from one ordered to a less ordered state of affair. When a substance is heated or cooled there is also a change in entropy. The entropy of a substance is a real physical quantity and is a definite function of the state of the body like pressure, temperature, the volume of internal energy. When a gas expands into a vacuum, water flows out of a reservoir, spontaneous chain reaction takes place, an increase in the disorder occurs and therefore entropy increases.Д®ntropy is the measure of the disorder or randomness in a system.

It is a measure of the disorder or randomness in the system.

Hence the state of the order of the molecules gets disturbed and gives rise to greater disorder.

Like temperature or pressure, it cannot be felt.

Hence spontaneous processes are accompanied by an increase in entropy as well as an increase in the disorder of the system.

The orderliness of an object decreases with the increase of entropy.

Like temperature, pressure, volume, internal energy, magnetic behavior it expresses the state of a body.A little consideration will show that when a spontaneous process takes place it moves from less probable state to a more probable state. It helps in determining the thermodynamic state of an object.All the natural processes are spontaneous processes. A spontaneous process is also known as an irreversible process because these processes take place at a very fast rate. It indicates the direction of heat flow.It is equal to the ratio of heat absorbed or rejected to the temperature. R/NA.Д®ntropy is very significant in thermodynamics. Where k denotes the Boltzmann constant which is equal to gas constant per single molecule i.e. This relationship is expressed by Boltzmann as: Hence, there is a close relationship between entropy S and the thermodynamic probability W of the state of the system. In a way, entropy is useful for knowing the efficiency of the internal energy of something. So entropy is useful in that it provides the information regarding structural changes accompanying a given process. Entropy is a measure of the part that cannot be used to do work. Alternately, entropy is the physical property of the body that remains constant in an adiabatic process. The thermal property that remains constant in an adiabatic process is called entropy.

Whats entropy