It provides a framework for relating the microscopic properties of individual atoms and molecules to the macroscopic or bulk properties of materials that can be observed in everyday life , therefore explaining thermodynamics as a natural result of statistics and mechanics ( classical and quantum ) at the microscopic level . Statistical mechanics provides a framework for relating the microscopic properties of individual atoms and molecules to the macroscopic bulk properties of materials that can be observed in everyday life , therefore explaining thermodynamics as a result of classical and quantum-mechanical description of statistics and mechanics at the microscopic level .