What is the typical energy range for photons in X-ray spectroscopy?

In X-ray spectroscopy, the energy range for photons is typically found between about 0.1 keV and 100 keV. This range corresponds to the energy levels associated with the electronic transitions that occur in X-ray interactions with matter, particularly in the context of inner-shell electrons. The energies in this range allow X-rays to penetrate materials effectively, facilitating the analysis of elemental composition and electronic structure.

When examining the other options, the range of 0.1 eV to 100 eV is too low for X-ray spectroscopy, as it falls into the ultraviolet and visible regions of the electromagnetic spectrum. Similarly, the range of 1 eV to 10 keV starts to include X-ray energies but does not capture the upper limits typical for X-ray use, which can extend above 10 keV. Lastly, a range of 0.1 keV to 10 MeV is much too high for the purposes of typical X-ray spectroscopy, as those energy levels venture into the gamma-ray region, where different physical phenomena occur. Therefore, the specified range of 0.1 keV to 100 keV accurately reflects the energies relevant for X-ray spectroscopy applications.