X-rays are used in determining the molecular structure of crystalline because

Step-by-step solution

Crystal structure is explored through the diffraction of waves having a wavelength comparable with the interatomic spacing (10⁻¹⁰ ~m ) in crystals. Radiation of longer wavelength cannot resolve the details of structure, while radiation of much shorter wavelength is diffracted through in conveniently small angles. Usually diffraction of X -rays is employed in the study of crystal structure as X-rays have wavelength comparable to interatomic spacing.