Discuss the experimental results of Geiger-Marsden's $\alpha$-particle scattering.

(N/A) The experimental results of the Geiger-Marsden $\alpha$-particle scattering experiment are summarized as follows:
$1$. $A$ typical graph of the total number of $\alpha$-particles scattered at different angles in a given interval of time is shown in the figure. The dots represent the experimental data points,and the solid curve is the theoretical prediction based on the assumption that the atom has a positively charged nucleus.
$2$. Most of the $\alpha$-particles pass through the gold foil without any significant deviation. This indicates that they do not suffer any collisions,implying that most of the space inside an atom is empty.
$3$. Only about $0.14 \%$ of the incident $\alpha$-particles scatter by more than $1^{\circ}$.
$4$. About $1$ in $8000$ $\alpha$-particles deflect by more than $90^{\circ}$,which suggests the presence of a small,dense,and positively charged nucleus at the center of the atom.