Which element was used in the Geiger-Marsden experiment for the gold foil tests?

In the Geiger-Marsden experiment, also known as the Rutherford gold foil experiment, gold was the key element used for the gold foil tests. This groundbreaking experiment was conducted to probe the structure of the atom. Researchers aimed to understand the nature of atomic structure by directing alpha particles at a very thin sheet of gold foil.

The choice of gold was crucial because it can be made extremely thin—only a few atoms thick—allowing alpha particles to pass through with minimal scattering if the atomic structure was as originally thought, with a positive charge distributed evenly throughout. However, the results revealed that a small percentage of alpha particles were deflected at large angles, leading to the conclusion that atoms have a dense, positively charged nucleus at their center, which drastically changed the models of atomic structure at the time.

Using other elements like aluminum, silver, or copper would not have provided the necessary conditions or clarity for these observations, as they do not possess the same properties that make gold particularly suitable for such experiments.