Question

Given figure shows a plot of binding energy per nucleon $E_{b}$ against the nuclear mass $M. A, B, C, D, E, F$ correspond to different nuclei. Consider four reactions

(i) $A+B \to C+\varepsilon$
(ii) $C \to A+B+\varepsilon$
(iii) $D+E \to F+\varepsilon$
(iv) $F \to D +E+\varepsilon$
Where $ \varepsilon$ is the energy released. In which reactions is $ \varepsilon$ positive?

• A. (i) and (iii)
• B. (ii) and (iv)
• C. (ii) and (iii)
• D. (i) and (iv)

Answer 1

Answer: (D)

Energy $\left(\varepsilon\right)$ is released when lighter nuclei fuse to form a heavier nucleus, such as in $(i)$
$A+B \to C+\varepsilon$
Again, energy is released when a heavy nucleus splits into lighter nuclei, such as in $(iv)$
$F \to D+E+\varepsilon$