A Gamma-Ray Photon of Energy 100 KeV Scatters Off an Electron

Multiple Choice

A gamma-ray photon of energy 100 keV scatters off an electron at an angle perpendicular to its original direction.Calculate the de Broglie wavelength of the recoiling electron.

A) 13.5 $\times$ 10^-12 m
B) 12.4 $\times$ 10^-12 m
C) 14.8 $\times$ 10^-12 m
D) 2.4 $\times$ 10^-12 m
E) 9.54 $\times$ 10^-12 m