One of the key ideas in classical chemistry is that every one chemical compounds may be represented as teams of atoms warranted along and chemical reactions may be represented because the creating and breaking of these bonds. Predicting the properties of chemical compounds from an outline of atoms and the way they bond is one in all the foremost goals of chemical science. Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium. Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a macroscopic or supra-molecular science, as the majority of the principles on which it was founded relate to the bulk rather than the molecular/atomic structure alone (for example, chemical equilibrium and colloids).