(a) Differentiate between nuclear fission and nuclear fusion.
(b) Deuterium undergoes fusion as per the reaction:
$_{1}^{2} H +_{1}^{2} H ⟶_{2}^{3} He +_{0}^{1} n + 3 \cdot 27 MeV$
Find the duration for which an electric bulb of 500 W can be kept glowing by the fusion of 100 g of deuterium.

Question

(a) Differentiate between nuclear fission and nuclear fusion.
(b) Deuterium undergoes fusion as per the reaction:
$_{1}^{2} H +_{1}^{2} H ⟶_{2}^{3} He +_{0}^{1} n + 3 \cdot 27 MeV$
Find the duration for which an electric bulb of 500 W can be kept glowing by the fusion of 100 g of deuterium.

Accepted Answer

Fission is the process of separating two heavy, unstable atomic nuclei into two lighter nuclei, also releasing energy, but less than with fusion. Fusion is where two light atomic nuclei unite and release energy.

Nuclear Fission	Nuclear Fusion
When the nucleus of an atom splits into lighter nuclei through a nuclear reaction the process is termed nuclear fission.	Nuclear fusion is a reaction through which two or more light nuclei collide with each other to form a heavier nucleus.
When each atom split, a tremendous amount of energy is released.	The energy released during nuclear fusion is several times greater than the energy released during nuclear fusion.
Fission reactions do not occur in nature naturally.	Fusion reactions occur in stars and the sun.
Little energy is needed to split an atom in a fission reaction.	High energy is needed to bring fuse two or more atoms together in a fusion reaction.
Atomic bomb works on the principle of nuclear fission.	Hydrogen bomb works on the principle of a nuclear fusion bomb.

(b) Number of atoms in 100g deuterium, $\frac{100}{2} \times 6 .023 \times 10^{- 23}$
Energy Released- $\frac{3.27}{2} x 1.6 x 10^{- 13} J$
Time required t = Total energy(E) / Power of lamp (P)
= 500 x 60 x 60 x 24 x 365
t = 1.5768 x 10¹⁰ years.