Calculate and compare the energy released by a) fusion of 1.0 kg of hydrogen deep within the sun and b) the fission of 1.0 kg of 235U in a fission reactor.
A. Amount of hydrogen, m=1kg=1000g 1 mole, i.e.e , 1 g of hydrogen (11H) contains 6.023×1023 atoms. Therefore 1000 g of hydrogen contains 6.023×1023×1000 atoms. Within the Sun, four 11H nuclei combine and form one 24He nucleus. In this process 26MeV of energy is released. Hence the energy released from fusion of 1kg 11H is E1=46.023×102326×103=39.149×1026MeV B: Amount of 92235U= 1 kg = 1000 g One mole i.e. 235 g of 92235U contains 6.023×1023 atoms. Therefore 1000 g of 92235U contains 2356.023×1023×1000 atoms. It is known that the amount of energy released in the fission of one atom of 92235 is 200MeV Hence, energy released from the fission of 1 kg of 92235 is E2=2356.023×1023×1000×200=5.106×1026MeV E2E1=7.67≈8 Therefore, the energy released in the fusion of 1 kg of hydrogen is nearly 8 times the energy released in the fission of one kg of uranium.
