Q104 / 180 · AIIMS 2006 · Physics
Which one of the following is a possible nuclear reaction?
- A${ }_5^{10} \mathrm{~B}+{ }_2^4 \mathrm{He} \rightarrow{ }_7^{13} \mathrm{~N}+{ }_1^1 \mathrm{H}$
- B${ }_{11}^{23} \mathrm{Na}+{ }_1^1 \mathrm{H} \rightarrow{ }_{10}^{20} \mathrm{Ne}+{ }_2^4 \mathrm{He}$
- Correct answerC${ }_{93}^{239} \mathrm{~Np} \rightarrow{ }_{94}^{239} \mathrm{Pu}+\beta^{-}+\bar{v}$
- D${ }_7^{11} \mathrm{~N}+{ }_1^1 \mathrm{H} \rightarrow{ }_6^{12} \mathrm{C}+\beta^{-}+\bar{v}$.
Solution
According to conservation of mass number
$$
10+4=13+1
$$
According to conservation of charge number, $5+2 \neq 7+1$
Hence (1) is not possible.
According to conservation of charge number, $93=94-1$
According to conservation of mass number, $239=239$
Hence (3) is possible.
According to conservation of mass number, $11+1=12$
According to conservation of charge number, $7+1 \neq 6-1$
Hence (4) is not possible.
${ }_{11}^{23} \mathrm{Na}+{ }_1^1 \mathrm{H}$ also satisfies both the conservation of mass number and charge. However, ${ }^{23} \mathrm{Na}$ is a very stable isotope and nuclear reaction will be very difficult. The formation of $\mathrm{Pu}$ from $\mathrm{Np}$ is well known. It satisfies the conditions of conservations and $\mathrm{Np}$ is also very unstable. Therefore (3) is the only correct answer.
Hence, the correct answer is option: 'C'.