Chemisorption is characterised by its high chemical specificity. The chemisorption binding energy is 1-10 eV, which leads to a significant amount of heat release. In chemisorption, there is an activation barrier, so when the temperature goes up, chemisorption accelerates. In some cases, the process may be irreversible. In chemisorption, the electronic structure of the surface may change significantly, resulting in the so-called chemical shifts of electronic levels, which can be analysed by molecular electronic spectroscopy. Strong interaction and a wide variety of interaction types make chemisorption drastically different for different systems, depending on the chemistry of adsorbates and adsorbents.