Aflat-plate x-ray diffraction pattern was cuka radiation. it consisted of a series of spots arranged along a horizontal line containing the central spot and first-order layer lines above and below the central line. it was found that with a specimen-to-film distance of 30 mm the first order lines were 22.9 mm above and below the central spot. (a) calculate the spacing of the chain repeat c of the polymer crystals. (b) explain why only first-order layer lines are observed for this polymer and suggest how higher order lines may be obtained. (c) determine the angle through which the specimen would have to be tilted in order to obtain the (001) reflection on the diffraction pattern.