Question

drive expression ofdistance of closest approach​

Answer 1

hey mate ☺

Distance of closest approach:

Distance of closest approach is the minimum distance between α–particle and Centre of nucleus just before it reflects back by 180°. Distance of closest approach is used to determine the approximate size of the nucleus. Size of nucleus is smaller than the distance of closest approach.

I hope it helps you ☺✌✌

Answer 2

Explanation:

K.E=1/2mv²

charge on alpha particle

q1=+2e

charge on scattering nucleus

q2=ze

now..

U= 1/4π€0 q1.q2/r0

U= 1/4π€0+2 e²z/r0

k.e= p.e

1/2 mv²=1/4π€02e²z/r0 (on cutting)

mv²= ze²/π€0r0

mv²π€0r0=e²Z (where r0 is a distance of closet approach)