Why was gold foil used in Rutherford’s scattering experiment?

In the famous experiment conducted by Ernest Rutherford and his associates, Hans Geiger and Ernest Marsden, gold foil was used primarily because it could be hammered into an extremely thin sheet—approximately 0.00004 cm thick.1

This extreme thinness was essential to the experiment's design, as it allowed a beam of alpha particles to pass through the material with minimal interference. By using such a thin target, the researchers could observe how the particles interacted with individual atoms rather than being blocked by a thick layer of matter.23

The results—where most particles passed straight through while a small fraction were deflected at large angles—provided the evidence needed to conclude that the atom consists of mostly empty space with its mass and positive charge concentrated in a tiny, dense nucleus.13