Nuclear forces are short-ranged and saturating, whereas electrostatic repulsion between protons acts over all distances inside a nucleus.
(a) Explain how these two facts together determine the general shape of the binding-energy-per-nucleon curve for all nuclei.
(b) On the basis of the competition between nuclear attraction and Coulomb repulsion, justify why nuclei with mass number close to 56 are the most stable.
(c) Suppose hypothetically that the range of the nuclear force were increased while its strength at short distances remained the same. Predict qualitatively how the position of the maximum of the binding-energy-per-nucleon curve would shift, if at all, and give reasons for your answer.