What fraction of 5 MeV α particles will be scattered through angles greater than 4.5° from a gold foil (Z = 79, density = 19.3 g/cm3) of thickness 10-8 m?

The fraction of particles is

Explanation:

Given :

Alpha particle atomic no.

Gold foil atomic number

Thickness m

Density

Kinetic energy of alpha particle V

V

Scattered angle 4.5°

Fraction of incident particle scattered at angle is,

Where number density of particle,

For calculating value of

Where ,           ( Mass number of gold foil )

Put the all value in above equation,

Therefore, the fraction of particles is