Compton effect

You scatter x-rays of wavelength 0.0119 nm from the loosely bound electrons of a target material. Find the angle at which the wavelength of the scattered x-rays is longer than the incident wavelength by a factor of f = 1.0339. 

Scattering on loosely bound electrons means this is Compton scattering.

The relation of wavelength for Compton scattering is

$\lambda2- \lambda1 = [h/(m*c)]*[1-cos(\theta)]$

$\lambda2 = 1.0339*\lambda1$

$(0.0339*\lambda1*m*c)/h =1-cos(\theta)$

$\lambda1 =0.0119 nm$

$m =9.1*10^{-31} kg$

$h =6.626*10^{-34}$

 $1-cos(\theta) =0.16621$

$\theta =33.5 degree$