i.Prove that the reason for energy to be liberated during the nuclear fission of a nucleus ^AX is that its fission fragments are more tightly bound. Assume that the number of prompt neutrons per fission reaction is two.

ii. The total mass of uranium in a certain reactor is 37 tonnes and the neutron flux is 6.7x1017 neutrons/m²/s. Assume that the cross-section of fission in ²³⁵U is 584 b and that the enrichment of ²³⁵U in the reactor is 4%. Calculate the rate of fission reactions