The law of thermodynamic
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Answer:
The laws of thermodynamics deal with energy changes of
macroscopic systems involving a large number of molecules
rather than microscopic systems containing a few molecules.
Thermodynamics is not concerned about how and at what
rate these energy transformations are carried out, but is
based on initial and final states of a system undergoing the
change. Laws of thermodynamics apply only when a system
is in equilibrium or moves from one equilibrium state to
another equilibrium state. Macroscopic properties like
pressure and temperature do not change with time for a
system in equilibrium state
The three laws of thermodynamics define physical quantities (temperature, energy, and entropy) that characterize thermodynamic systems at thermal equilibrium. The laws describe how these quantities behave under various circumstances, and preclude the possibility of certain phenomena (such as perpetual motion).
The three laws of thermodynamics are
First law of thermodynamics: When energy passes, as work, as heat, or with matter, into or out from a system, the system's internal energy changes in accord with the law of conservation of energy. Equivalently, perpetual motion machines of the first kind (machines that produce work with no energy input) are impossible.
Second law of thermodynamics: In a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems increases. Equivalently, perpetual motion machines of the second kind (machines that spontaneously convert thermal energy into mechanical work) are impossible.
Third law of thermodynamics: The entropy of a system approaches a constant value as the temperature approaches absolute zero.[] With the exception of non-crystalline solids (glasses) the entropy of a system at absolute zero is typically close to zero.
In addition, there is conventionally added a "zeroth law", which defines thermal equilibrium:
Zeroth law of thermodynamics: If two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other. This law helps define the concept of temperature.
There have been suggestions of additional laws, but none of them achieve the generality of the four accepted laws, and they are not mentioned in standard textbooks.
The laws of thermodynamics are important fundamental laws in physics and they are applicable in other natural sciences.