In a Compton scattering experiment, X-rays of wavelength λ are scattered at an angle θ. Which parameter remains unchanged in the collision?
Correct: C
In Compton scattering, the Compton wavelength (2.43 pm) is a fundamental constant and remains unchanged. The photon’s energy and wavelength change depending on the scattering angle, but the Compton wavelength (a property of the electron) is invariant.