In the framework of a unified kinetic theory of particle-surface interactions, dependences of the relaxation, accommodation, and trapping of molecules on their angular momentum J are discussed. One of the basic parameters of the theory, the free flight time through the interaction region, is calculated using a simple model potential for which the classical equations of motion can be integrated analytically. With increasing J, an increase in molecular relaxation and accommodation is predicted at small J, and a decrease at larger J. These results constitute a microscopically founded interpretation of recent experiments on surface light-induced drift.