Cross section and asymmetry parameter profiles for the ionizations of the valence and core shells of the second-row hydrides have been calculated by the time-dependent density functional theory (TD-DFT) and Kohn-Sham (KS) schemes. The importance of the screening effects has been pointed out by the comparison of the KS and TD-DFT results and has been analyzed in detail for the HCl molecule. The results have been discussed with respect to the nature of the ionized orbitals along the series in order to assess the observed trends. This behavior of the Cooper minima in the outer valence molecular orbitals has been considered in detail both in the cross section and asymmetry parameter profiles. The TD-DFT results, compared with the experimental data, show quantitative agreement with the experiment for the outer-valence and core ionizations. A deterioration of the quality of the TD-DFT results is still present in the inner-valence region. (C) 2003 American Institute of Physics.