definition of physical reaction in chemistry
II. Vocabulary: 1  Physical Reaction: The matter stays the same, but change in size, shape, or appearance. 2  Chemical Reaction: The matter changes to a different kind of matter, or change in color. 3  Concentration: amount of substance dissolved in a certain amount of solvent.
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of laws and concepts of physics.