Which statement is true about coherent scattering?

Which statement is true about coherent scattering?

• A. It involves energy loss of the photon
• B. It is a type of elastic scattering
• C. It produces a scattered photon with altered wavelength
• D. It heats the target

Answer: (B)

Coherent scattering, also known as Rayleigh scattering, involves the X-ray photon interacting with the entire atom in a way that leaves the atom in its original state. Because no energy is transferred to the atom, the process is elastic, so the photon keeps essentially the same energy (and wavelength) while its direction changes. This is different from processes like Compton scattering, where the photon loses energy and its wavelength increases, or from absorption/scattering that would heat the target. So, describing coherent scattering as a type of elastic scattering correctly captures the essential feature: energy is conserved and only the direction of the photon changes.

Coherent scattering, also known as Rayleigh scattering, involves the X-ray photon interacting with the entire atom in a way that leaves the atom in its original state. Because no energy is transferred to the atom, the process is elastic, so the photon keeps essentially the same energy (and wavelength) while its direction changes. This is different from processes like Compton scattering, where the photon loses energy and its wavelength increases, or from absorption/scattering that would heat the target. So, describing coherent scattering as a type of elastic scattering correctly captures the essential feature: energy is conserved and only the direction of the photon changes.