 When working under practical, everyday conditions, high energy-resolution settings will produce peak widths (FWHM) between 0.4–0.6 eV for various pure elements and some compounds.For example, in a spectrum obtained in 1 minute at a pass energy of 20 eV using monochromated aluminum Kα X-rays, the Ag 3"d"5/2 peak for a clean silver film or foil will typically have a FWHM of 0.45 eV.Non-monochromatic magnesium X-rays have a wavelength of 9.89 angstroms (0.989 nm) which corresponds to a photon energy of 1253 eV.