Rutherford scattering formula fails for ...

Rutherford scattering formula fails for very small scattering angles because

the kinetic energy of alpha particles is larger

the gold foil is very thin

the full nuclear charge of the target atom is partially screened by its electrons

all of these

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At the suggestion of Earnest Rutherford, hans Geiger and ernest Marsden bombarded a thin gold foil by alpha -particles from a polonium source. It was expected that alpha -particles would go right through the foil with hardly any deflection. Although, most of the alpha particles indeed were not deviated by much, a few were scattered through veryi large angles. Some were even scattered in the backward direction. The nly way to explain the results, rutherford found, was to picture an atom as being compoed of a tiny nucleus in which its positive charge and nearly all its mass are concentrated. Scattering of alpha -particles is proportional to target thickness and is inversely proportional to the fourth power of sin((theta)/(2)) , where, theta is scattering angle. Distance of closest approach may be calculated as: r_("min")=(Z_(1)Z_(2)e^(2))/(4piepsi_(0)K) where, K=kinetic energy of alpha -particles. Q. Rutherford's scattering formula fails for vary small scattering angles because:

The gold foil is very thin

the kinetic energy of `alpha`-particle is very high

The full nuclear charge of the target atom is partially screened by its electron

There is strong repulsive force between the `alpha`-particles and nucleus of the target.

`b prop sec^2 theta `

`b prop sec^3 theta `

`b prop tan ""((theta)/(2))`

`b prop cot ""(theta /2)`

`oo`

Data is insufficient