For ten points, identify this phenomenon where waves bend around an obstacle.
The intensity of this process for electrons is proportional to the structure factor squared, and one parameter for this phenomenon measures the ratio of aperture size squared to the product of distance and wavelength. Due to this process, every point on a wave front is considered a source of (*) secondary spherical wavelets, and this interaction creates an Airy disk that limits the focusing ability of lenses. Interference caused by this phenomenon creates alternating light and dark bands, which was observed in Young's double-slit experiment. For ten points, identify this phenomenon where waves bend around an obstacle.
The intensity of this process for electrons is proportional to the structure factor squared, and one parameter for this phenomenon measures the ratio of aperture size squared to the product of distance and wavelength.
diffraction [accept x-ray scattering before "ratio"]