Draw the diagram representing the schematic arrangement of Geiger-Marsden experimental alpha particle scattering.

Explanation

The source of `alpha`-particle are taken from `alpha`-decay of `._83^214Bi`. Gold foil used is of thickness 0.21 micron. The scattered `alpha`-particles were discovered by rotatable detector with a fluorescent flashes on the screen . The intensity of `alpha`-particles is studied as the function of `.theta.` . According to the law of conservation of energy
K.E.=P.E.
i.e., `1/2mv^2=1/(4piepsilon_0)(2Ze^2)/r_0`
where `.r_0.` is the closest approach of `.alpha.` particle
where , `K=1/2mv^2`
Experimental conclusions :
The impact parameter `I_p=2r_0 cot (theta//2)`
For a wide range of `theta , alpha` particles travel straight because of small deflection. For `theta=180^@, I_p=0` , the `alpha`-particle when directed towards the centre (for a head-on collision) , it retraces the path. Thus , the impact parameter is inversely proportional to tan `(theta//2)` .