  It has been known for several decades that transport of chemical elements is
induced by the process of microscopic atomic diffusion. Yet, the effect of
atomic diffusion, including radiative levitation, has hardly been studied in
the context of gravity mode pulsations of core-hydrogen burning stars. In this
paper, we study the difference in the properties of such modes for models with
and without atomic diffusion. We perform asteroseismic modeling of two slowly
rotating A- and F-type pulsators, KIC11145123 ($f_{\rm rot} \approx0.010~{\rm
d}^{-1}$) and KIC9751996 ($f_{\rm rot} \approx0.0696~{\rm d}^{-1}$),
respectively, based on the periods of individual gravity modes. For both stars,
we find models whose g-mode periods are in very good agreement with the {\it
Kepler\/} asteroseismic data, keeping in mind that the theoretical/numerical
precision of present-day stellar evolution models is typically about two orders
of magnitude lower than the measurement errors. Using the Akaike Information
Criterion (AIC) we have made a comparison between our best models with and
without diffusion, and found very strong evidence for signatures of atomic
diffusion in the pulsations of KIC11145123. In the case of KIC9751996 the
models with atomic diffusion are not able to explain the data as well as the
models without it. Furthermore, we compare the observed surface abundances with
those predicted by the best fitting models. The observed abundances are
inconclusive for KIC9751996, while those of KIC11145123 from the literature can
better be explained by a model with atomic diffusion.
