Statistical mechanics isÂ the branch of theory of physics studying the use ofÂ probability theory and also the Average or mean behaviour of an mechanical system wherein the state of the system is said to be uncertain.

The commonly use of this mechanics is is in the thermodynamic accomplishmentÂ of large systems. The statistical thermodynamics or the statistical mechanics are the branches of statistical mechanics.

The advantage of using this mechanics is to provide exact methods ofÂ connecting the thermodynamic quantities to the microscopic behaviour. The statistical form of mechanics also makes possible in extending the laws of thermodynamics with few or some degrees of freedom.

Statistical Thermodynamics:

The statistical thermodynamics helps in derivation of theÂ classical thermodynamics of various materials coming in terms of property ofÂ the constituent particles and also interaction between them. In simple ways, statistical thermodynamics givesÂ an connection between macroscopic properties of the materials coming in thermodynamic equilibrium and also the microscopic behaviour as well as theÂ motions that occursÂ inside the material. Whereas the statistical mechanics involves dynamics and is mainly focused on the statistical equilibrium.

Non-equilibrium

There are a variousÂ physical phenomenon of interest whichÂ involves quasi-thermodynamic processes of equilibrium, here areÂ some of the examples

- The transport of heat by internal motions within a material, is driven by an imbalance in theÂ temperature.
- The Electric currents that are carried by motion of the charges in an conductor, is well driven byÂ imbalance in the voltage.
- A Spontaneous chemical reaction is driven by the decrease in the free energy.
- Friction, quantum decoherence & dissipation.
- Systems that are being pumped by the external forces.
- In general, an Irreversible process

Stay tuned with byju’s to learn about statistical mechanics and many more.