absorption edge

An absorption edge is a sharp change in how a material absorbs X-rays or light at a specific energy level. It occurs when the energy of the incoming radiation is just enough to eject tightly bound electrons from atoms within the material. At this precise energy, absorption significantly increases, creating a noticeable feature called the "edge" in the absorption spectrum. This property helps scientists identify and analyze the composition of materials, as different elements have characteristic absorption edges corresponding to their electron binding energies.