Calculate and compare the energy released by a) fusion of 1.0 kg of hydrogen deep within Sun and b) the fission of 1.0 kg of ²³⁵U in a fission reactor.

a) Mass of hydrogen, m = 1kg = 1000 g

Since,1 mole of hydrogen contains 6.023×10²³ atoms which is equivalent to 1 g of hydrogen then, 1kg of hydrogen contains,

N = 6.023×10²³×1000 = 6.023×10²⁶ atoms

In sun, 4 hydrogen atoms, combine to form one helium atom, in fusion process which releases 26 MeV of energy.

Thus,

Energy released from fusion of 1kg of hydrogen is,

……………….(1)

=

b) Mass of uranium, m = 1kg = 1000 g

Since,1 mole of Uranium contains 6.023×10²³ atoms which is equivalent to 235 g of Uranium then, 1kg of Uranium contains,

N =

During fission reaction of 1 atom of releases 200 MeV of energy.

Thus,

Energy released from fission of 1kg of Uranium is,

………..(2)

Divide (1) by (2) we get,

Hence, Fusion reaction occurred in Sun releases 8 times more energy than energy released during the fission reaction of Uranium.