In the study of Geiger-Marsden experiment on scattering of alpha particles by a thin foil of gold, draw the trajectory of alpha-particles in the coulomb field of target nucleus, Explain briefly how one gets the information on the size of the nucleus from this study.

Explanation

The trajectory of alpha - particle in the Coulombain field of tragest nucleus is show in fig. 12.05 By experimental study of large angle scattering of high energy c-particles, value of distance of closest approach .`r_(0)`. was determined. The distance of closest approach can be either equal to or greater than the nuclear radius .r. i.e.`r_(0)ge r`, P2r
Thus, by knowing the value of distance of closest approach we can estimate the size of the nucleus. The estimated size comes out to be about 10 times the size of an atom.