Looking at the binding energy per nucleon vs mass number ($A$) curve, the binding energy per nucleon is MAXIMUM near which mass number?

1. NCERT §13.4 (Fig. 13.1) plots binding energy per nucleon $E_{bn}$ as a function of $A$. 2. The curve rises rapidly for small $A$, reaches a broad peak near iron ($A \approx 56$, $\,^{56}\mathrm{Fe}$), and then slowly decreases. 3. At the peak: $E_{bn} \approx 8.8\,\text{MeV}$ per nucleon. This makes nuclei in the iron region the most TIGHTLY BOUND nuclei in nature. 4. Two important consequences: • Light nuclei (e.g. hydrogen, deuterium) can release energy by FUSING to form heavier nuclei closer to iron — basis of stellar energy and fusion reactors. • Very heavy nuclei (uranium, plutonium) can release energy by FISSION to produce two mid-mass fragments closer to iron — basis of nuclear power and weapons. 5. Options A, C, D refer to nuclei AWAY from the maximum, where $E_{bn}$ is lower. _Source: NCERT Class 12 Physics Part 2, Ch 13, §13.4 (Fig. 13.1 + discussion), p. 5–6._