Answer the following questions related to mass defect and nuclear binding energy.
a. (i) Define the term mass defect of a nucleus.
b. (ii) Using Einstein’s mass–energy equivalence, explain how the mass defect of a nucleus is related to its binding energy.
c. (iii) Binding energy per nucleon is generally taken as a better indicator of nuclear stability than the total binding energy of the nucleus. State and explain any two reasons for this preference.