K-edge absorption

K-edge absorption refers to a sharp increase in the ability of an element's atoms to absorb X-ray or gamma-ray photons at a specific energy. This occurs when the photon energy matches the energy needed to eject an inner-shell (K-shell) electron from the atom. The energy at which this jump happens is characteristic of each element, making K-edge absorption useful for identifying and analyzing materials. It's a fundamental principle in techniques like X-ray spectroscopy, where it helps determine the composition of objects by observing how their atoms interact with high-energy photons.