A model potential calcn. was made for Ar scattering by Na and K in the ground state and the resonance state. The model potential has only 2 free parameters which are detd. by a best fit of the interat. potentials to exptl. results. Satisfactory agreement between calcd. and exptl. results is found for the differential cross sections in the ground state and the excited state, for satellites in the K(4P), K(5P), and Na(3P) line profiles, for the van der Waals consts. C(6) and C(8), the alk. ion-rare gas interaction, and the vibrational energy levels of the Na-Ar mol.