Question

The following figure represents the liquid drop model of nuclear fission. The energies of these states are $E_1$, $E_2$ and $E_3$respectively. Which option is correct?

• A. $E_1$>$E_2$>$E_3$
• B. $E_1$>$E_2$<$E_3$
• C. $E_1$<$E_2$>$E_3$
• D. $E_1$<$E_2$<$E_3$

Answer 1

The correct option is C $E_1$<$E_2$>$E_3$

A nuclear fission doesn't require external energy supply. It's a spontaneous process in which the energy of the system must decrease. So the correct option is $E_1$>$E_2$>$E_3$. Right ? No. Wrong !!
What we said about the spontaneity of the fission process is totally correct, but the energy of the intermediate state is higher than that of the parent nucleus and then the energy decreases. Yes, shocking! If we didn't supply any energy for fission to happen, how did the energy of intermediate state increase in the first place?
The answer lies in the realms of "Quantum Mechanics".
Take it for granted as of now.
So, we conclude by saying that the energy of the parent nucleus is less than the energy of the intermediate state and the energy of the daughters are less than all. Look at the graph as well to visualize the variation.
Once the lobes are formed since we can see that both the lobes are positively charged, the electrostatic repulsion finally breaks it apart into two individual fragments. (Diag. c)