Final answer:
The relative number of X-rays that undergo Compton interactions indeed increases with higher x-ray energy, as Compton effect is more significant in such cases due to its dependence on the electron density and material thickness.
Step-by-step explanation:
The statement that the relative number of X-rays that undergo Compton interactions increases is true. As the x-ray energy increases, Compton scattering becomes a more significant mode of attenuation. X-rays scatter from the outer electron shell of an atom, transferring kinetic energy to the ejected electron and losing energy in the process. The likelihood of attenuation depends on the electron density and the material thickness, where the chemical composition and atomic number have less significance in Compton scattering. Lower energy X-rays offer better image contrast, but are more readily absorbed when passing through dense materials. To enhance contrast, substances with a high atomic number like barium or iodine can be introduced.
It is also important to note an error in the provided reference material that suggests ultraviolet light has higher energy than X-rays, which is incorrect. X-rays carry more energy than ultraviolet light, thus affecting the likelihood of detecting Compton scattering.