 Chemisorption, chemisorption is a kind of adsorption which involves the chemically reaction between the surface and the adsorbate. New chemical bonds are generated at the adsorbing surface. Examples include macroscopic phenomena that can be very obvious, like corrosion, and sufferer effects associated with heterogeneous catalysis. The strong interaction between the adsorbate and the substrate surface creates new types of electronic bonds. In contrast with chemisorption is visisorption, which leaves the chemically species of the adsorbate and surface intact. It is conventionally accepted that the energetic threshold separating the binding energy of visisorption from that of chemisorption is about 0.5 F per adsorbed species. Due to specificity, the nature of chemisorption can greatly differ, depending on the chemical identity and the surface structure.