1. The problem statement, all variables and given/known data Photons and electrons interact via Compton scattering. If the photon scattering angle is θ=30, compute the relative change in wavelength for photons of wavelength λ=10-2 m. Is the photon scattering elastically? (The electron Compton wavelength is: λc=2.4x10-12m) I've solved this problem as so: Δλ = λc(1-cosθ) = 3.22x10-13 So the relative change in wavelength: Δλ / λ = 0.322 I believe this isn't elastic scattering but I don't really understand why. Any help would be appreciated.