DefinitionAn <ACTIVITY FACTOR REFERENCED TO HENRY'S LAW> is an <IndirectProperty> where there are three different cases for the activity factor referenced to Henry's law: molality basis, gamma_m, <CONCENTRATION> basis, gamma_c, and amount-of-substance basis, gamm_z: gamma_m,B = a_m,B/(b_B/b^Theta); gamma_c,B = a_c,B/(c_b/c^Theta); gamma_x,B = a_x,B/x_B