Instead of giving atomic masses for nuclides as in Appendix B some Tables give the mass excess,

Question:

Instead of giving atomic masses for nuclides as in Appendix B some Tables give the mass excess, ∆ defined as ∆ = M – A, where A is the atomic number and M is the mass in u. Determine the mass excess in u and in MeV/c2, for:
(a) 4/2He;
(b) 12/6C;
(c) 107/47Ag;
(d) 235/92U.
(e) From a glance at Appendix B, can you make a generalization about the sign of ∆ as a function of Z or A?