Some fifth-period elements Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag and Cd have been obtained in powder form and converted into pellets by applying pressure (similar to 1 GPa). They have annealed at 1000 degrees C (except Cd similar to 300 degrees C). In the external magnetic fields (0.4 and 0.8 T) and without magnetic field, the coherent to Compton differential cross-sectional ratios has been investigated by using energy-dispersive X-ray fluorescence system. The data were analyzed via Origin 9.0 computer program. The results were calculated experimentally and theoretically. The theoretical results were obtained with two different methods, and these results were compared with the experimental results. These methods are relativistic form factor theory and non-relativistic form factor theory at without magnetic field. It was seen that the coherent to Compton differential cross-sectional ratios of the elements used in the present study increases with the increasing of the magnetic field and atomic number.