XRF radiation returns as what type of rays?

XRF, or X-ray fluorescence, involves the emission of X-rays as a result of irradiating a sample with high-energy X-rays or gamma rays. When these high-energy X-rays interact with the atoms in the sample, they can cause the electrons in the atoms to be ejected. As the atom returns to a stable state, it emits energy in the form of secondary X-rays. This phenomenon specifically highlights that the radiation return from the XRF process is indeed X-rays.

In this context, while electromagnetic waves encompass a broad category that includes X-rays, the specificity of the question focuses on the type of rays emitted during the XRF process, which are X-rays. Therefore, this option accurately reflects the physics of the XRF method. Understanding this distinction is crucial, as it distinguishes the characteristics and types of radiation produced in various contexts, particularly in analytical chemistry and material analysis.