Comparison between shell model and liquid drop model.

A comparative study between the single particles shell model and the liquid drop model according to Niels Bohr is that both are in conflict it each other In the shell model, it has been assumed that each nucleon moves in its orbit within the nucleus, independently of all other nucleons. The orbit determined by a potential energy function V(r). Each nucleon is regarded as an independent particle and the interaction between nucleons is considered to be a small perturbation on their action between the orbital nucleon and the rest is very weak in the liquid drop model,on the otherhand the nucleons are considered to interact strongly with each other so that the collective motions are possible. The following three examples speak infavour ofsuch collective motions-
(1) The phenomenon of nuclear fission which can be easily descr in terms of free vibrations of a liquid drop.
(2) The large values of electric quadruple moment in some nude cannot be accounted for on the single particle shell model. The discrepancy between the theoretical be explained only on de and experimental values can assumption that collective distortions nuclear core involving many of the nucleons also contribute to the quadruple moment.
(3) The third example is observed mean lines for ramna radiation of the electric quadruple type.
The observed lines are approximately 100 times shorter than estimated on the assumption that moves during the transition. This only one proton suggests that changes in the deformation of the core are involved.