Adsorption isotherms of localized monolayers

The adsorbed molecule is bound in a low energy position this position constitutes an active site. 

The solid s surface is now made up of identical active sites that we will assimilate to active species, which we will denote by s. 

Adsorption can then be expressed as an actual chemical reaction for which we 

To express the equation of the isotherm, there are two complementary and equally effective methods available. 

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