δ Scuti stars are intermediate-mass stars that pulsate in low-order pressure modes and show rich frequency spectra in both space-based and ground-based photometry. This makes them an ideal testbed for asteroseismology. Pulsations in these stars are driven mainly by the He II opacity bump, which traps radiation during compression and releases it during expansion. There is a class of stars that show an overabundance of iron-group elements at the surface and are non-magnetic; these are known as Am stars. Atomic diffusion and radiative levitation play a major role in sustaining these surface chemical features. The envelope of these stars is radiative and relatively quiet, as no significant convection is present. This allows helium to settle downwards under gravity, and the ionization zone weakens over time. However, some Am stars do show δ Scuti pulsations, and in this thesis we have investigated several of them using asteroseismology. We have used the CLÉS, OSC, and MAD codes to evolve stellar models and to compute their radial modes with both adiabatic and non-adiabatic methods, and no significant difference was observed for the low radial-order modes. Different overshooting parameters were used to extend the convective core boundary, and up to 0.3 times the pressure scale height the seismic analysis produces similar results. We also examined different values of the mixing-length parameter, which corresponds to the efficiency of convective energy transport, and found that on the ZAMS and the early main sequence the evolutionary tracks nearly overlap, leading to a similar conclusion. Amplitude modulation is a common phenomenon seen in the frequency spectra of δ Scuti stars, and here we have studied and reported such modulation in Am stars.