If `M(A,Z)`, `M_(p)and M_(n)` denote the masses of the nucleus `._(Z)X^(A)`, proton and neutron respectively in units of U (where`1U=931MeV//c^(2)`) and B.E. represents its B.E. in MeV, then

Options

A. `M(A,Z)=ZM_(p)+(A-Z)M_(n)-BE`
B. `M(A,Z)=ZM_(p)+(A-Z)M_(n)+BE//C^(2)`
C. `M(A,Z)=ZM_(p)+(A-Z)M_(n)-BE//C^(2)`
D. `M(A,Z)=ZM_(p)+(A-Z)M_(n)+BE`

Answer

C

Explanation

Mass defect
`Deltam=ZM_(p)+(A-Z)M_(n)-M(A,Z)`
Binding energy `=DeltamC^(2)`
`BE=[ZM_(p)+(A-Z)M_(n)-M(A,Z)].C^(2)`
`M(A,Z)=ZM_(p)+(A-Z)M_(n)-(BE)/(C^(2))`