x-ray scattering

  

x-ray of wavelength 1Ao are incident on a material.

(a) The ejected electrons at a certain angle ???? have kinetic energy 200 ev. Find the angle θ at which the photons where scattered that caused ejection of these electrons.

(b) What is the maximum kinetic energy that ejected electrons can have for these x-rays and at which angle θ are they ejected?