calculate mass defect ,binding energy and binding energy per nucleon for a lithium nucleus taking it mass 7amu.

Asked by Mukesh Kumar Mahto | 2nd Nov, 2010, 12:00: AM

Expert Answer:

Dear student
You may use following information and equations to calculate the mass defect, binding energy and binding energy per nucleon for lithium, taking its mass as 7 amu.

The actual mass of a nucleus is always found to be less than the sum of the masses of the nucleons present in it . The mass difference is known as the mass defect and is denoted by  .

Consider nucleus of an element  ZXA with the mass number 'A' and atomic number 'z' . This element contains 'z' protons and ( A - z ) neutrons . Hence , mass of the constituent nucleons ( M' )  .

( M' )  =  z mp  +  ( A - z ) mn       ------------> (1)

Where mp  and  mn are the masses of the proton and neutron respectively .

If 'M' is the actual mass of the nucleus of the element then the mass defect is  

m   =   [ zmp +  (A - z)mn ]  -  m        

Binding energy B.E  =      931.5  MeV 
B.E./ nucleon = B.E. / mass no.
We hope this clarifies your doubt.

Answered by  | 13th Dec, 2010, 02:33: PM

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