What radioactive source did Geiger and Marsden use in the scattering experiment?

Describe the Geiger-Marsden scattering experiment.

Which one did Rutherford consider to be supported by the results of experiments in which $\alpha - $ particles were scattered by gold foil?

In a Rutherford scattering experiment,when a projectile of charge $Z_1$ and mass $M_1$ approaches a target nucleus of charge $Z_2$ and mass $M_2$,the distance of closest approach is $r_0$. The energy of the projectile is:

$\sqrt{d_{1}}$ and $\sqrt{d_{2}}$ are the impact parameters corresponding to scattering angles $60^{\circ}$ and $90^{\circ}$ respectively,when an $\alpha$-particle is approaching a gold nucleus. For $d_{1} = x d_{2}$,the value of $x$ will be . . . . . .

State the atomic hypothesis regarding the structure of matter.