Surface chemistry is a branch of chemistry that deals with the study of chemical reactions and processes that occur at the interface of two phases, such as a solid and a gas or liquid. The properties and behavior of materials at the surface can differ significantly from those in the bulk, making surface chemistry an important area of study for understanding various phenomena such as adsorption, catalysis, corrosion, and surfactant behavior. Researchers in this field often use techniques such as spectroscopy, microscopy, and surface analysis to investigate the structure, composition, and reactivity of surfaces at the atomic and molecular level.