Arrange the following in increasing order of binding energy per nucleon
A. Li
B. Fe
C. O
D. N
E. H
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \( E \lt A \lt D \lt C \lt B \)
On the binding energy per nucleon curve, \( E_{bn} \) rises steeply for light nuclei as the mass number increases and reaches its maximum (about 8.75 MeV) near iron, \( A = 56 \).
Approximate values for the common isotopes:
\( \mathrm{H}: \approx 0 \;(\text{a single proton; about } 1.1\,\mathrm{MeV}\ \text{for}\ {}^{2}\mathrm{H}) \)
\( {}^{7}\mathrm{Li}: \approx 5.6\,\mathrm{MeV} \)
\( {}^{14}\mathrm{N}: \approx 7.5\,\mathrm{MeV} \)
\( {}^{16}\mathrm{O}: \approx 8.0\,\mathrm{MeV} \)
\( {}^{56}\mathrm{Fe}: \approx 8.8\,\mathrm{MeV} \)
\( \mathrm{H} \lt \mathrm{Li} \lt \mathrm{N} \lt \mathrm{O} \lt \mathrm{Fe} \)
In terms of the labels: E < A < D < C < B.
NCERT (2026-27):
Nuclear Binding Energy – “… Figure 13.1 is a plot of the binding energy per nucleon Ebn versus the mass number A for a large number of nuclei. … The curve has a maximum of about 8.75 MeV for A = 56 and has a value of 7.6 MeV for A = 238. (ii) Ebn is lower for both light nuclei (A<30) and heavy nuclei (A>170).”
