In this experiment alpha particles were used to hit a very thin golden foil. My question is if the foil were not made exactly of just one layer of atoms could it be that in case the multiple layers atoms were not overlapping each other the resulting density of nuclei would be higher to a maximum density of n*d, where 'n' is the number of layers and 'd' the density of just one layer of atoms so the result would be different for different parts of the foil regarding their thickness?
I'm not 100% sure what you are asking. I guess you are asking: "Does the result depend on the thickness of the used material." If so, the answer is YES!
Please read the abstract of the original paper. It says:
The following are the chief points investigated:— (1) Determination of the amount of scattering produced in different thicknesses of the same material. (2) Comparison of the amounts of scattering produced in different materials. (3) Relation between the velocity of the α-particles and the amount of their scattering.