Physical chemistry is the application of physics to macroscopic, microscopic, atomic and particulate phenomena in chemical systemswithin the field of chemistry traditionally using the principles, practices and concepts of thermodynamics, quantum chemistry, statistical mechanics and kinetics.Quantum Chemistry (p3 - "PHYSICAL CHEMISTRY"), states that "We can divide physical chemistry into four areas: thermodynamics, quantum chemistry, statistical mechanics and kinetics". It is mostly defined as a large field of chemistry, in which, several sub-concepts are applied; the inclusion of quantum mechanics is used to illustrate the application of physical chemistry to atomic and particulate chemical interaction or experimentation Physical Chemistry (p3 - "PHYSICAL CHEMISTRY"), states that the field of physical chemistry is concerned with the microscopic and the macroscopic phenomenon which are mostly concerned with thermodynamics, and kinetics; the field of atomic and particulate interaction being included is implied with the inclusion of quantum chemistry..