If $\alpha$ -particle scattering experiment is carried out using a foil of any metal as thin as gold foil used by Rutherford, there would be no change in observations. But since other metals are not so malleable so, such a thin foil is difficult to obtain. If we use a thick foil, then more $\alpha$ – particles would bounce back and no idea about the location of positive mass in the atom would be available with such a certainty.