Transport of chemical elements in main-sequence stars is still far from understood and leads to large uncertainties in stellar models. The competition between all transport processes leads to variations of stellar abundances and this is only when we will include all these processes in stellar evolution codes, that we will be able to explain surface abundances and internal structure of stars. For example atomic diffusion, including the effect of radiative accelerations on individual elements, leads to variations of the chemical composition inside the stars as well as the surface abundances evolution. Indeed the accumulation in specific layers of the elements, which are the main contributors of the local opacity, modifies the internal stellar structure and surface abundances. Using asteroseimology, we showed that the variations of the chemical composition induced by atomic diffusion and the mixing induced by the rotation in G and F type stars can have significant impact on their structure, stellar parameters and seismic properties. These processes need to be taken into account in stellar evolution models as the observations are more and more precise, especially in the context of the space missions Kepler, TESS and in the future PLATO.