Question

xrays of wavelength 0.4500 nm are scattered from free electrons in a target . what is the wavelength of photons scattered at 60 relative to incident rays

Answer 1

The formula is :

Y' = Y + hc / mc² (1 - Cos Ф)

Where Y' = wavelength of the scattered X ray.

Y = Initial wavelength = 0.4500nm

h = planks constant

c = speed of light

m = Mass of the recoiling particle and in this case it is an electron.

Useful constants :

hc = 1240eV

mc² = 511 keV

Doing the substitution we have :

Y' = 0.45nm + (1240eV / 511000eV) × (1 - Cos 60)

= 0.45nm + 2.426 × 10⁻³ × 0.5

= 0.45nm + 1.213 × 10⁻³

= 0.451213nm