Binding energy per nucleons vs mass curve for nucleus is shown in the figure `W,X,Y`and `Z` are four nuclei indicated on the curve . The process that would release energy is

Options

A. `Y rarr 2Z`
B. `W rarr X + Z`
C. `W rarr 2Y`
D. `X rarr Y + Z`

Answer

C

Explanation

Energy is released in process when total binding energy of the nucleus (=binding energy per nucleon `xx` number of nucleons) is increased or we can say, when total binding energy of products is more than the reactants. By calculation we can see that only in case of option (c), this happens.
Given : `W rarr 2Y`
Binding energy of reactants `=120xx7.5`
`=900 MeV` and binding energy of products
`=2(60xx8.5)=1020 MeV gt 900 MeV`.