Models of the atom
A: Nucleon number (Mass number)
Z: Atomic number (Proton number, also number of electrons in a neutral atom)
Rutherford's Alpha Scattering Experiment
Rutherford was also helped by two of his students, Geiger and Marsden.
R: When the original experiments were being completed, particle accelerators weren't available so Rutherford required a natural probe. He used Radon gas which emits alpha particles. Since it emits radiation equally in all directions, the beam was collimated to ensure accuracy of measurements.
F: Gold foil was used as a target. It was ideal for the experiment since it can be rolled out to be just a few atoms thick. This was important since alpha radiation can be absorbed by a piece of paper.