Describe the Geiger-Marsden scattering experiment.

(N/A) In the Geiger-Marsden experiment,a beam of $5.5 \text{ MeV}$ $\alpha$-particles emitted from a ${ }_{83}^{214} \text{Bi}$ radioactive source is directed at a thin gold foil.
The $\alpha$-particles are collimated into a narrow beam by passing them through lead bricks.
This beam is allowed to strike a thin gold foil of thickness $2.1 \times 10^{-7} \text{ m}$.
The scattered $\alpha$-particles strike a fluorescent screen (typically $\text{ZnS}$),producing brief light flashes known as scintillations.
These scintillations are observed through a rotatable microscope,allowing the study of the number of scattered particles as a function of the scattering angle $\theta$.