Question

A nuclear transformation is denoted by $X(n,\alpha ){\to }_3^{7}Li$. Which of the following is the nucleus of element $X$?

• A. ${}_6^{12}C$
• B. ${}_5^{10}B$
• C. ${}_5^{9}B$
• D. ${}_4^{11}Be$

Answer 1

Answer: (B)

${}_5^{10}B$

$\begin{array}{cc}& X(n,\alpha )⟶{}_3^7{L}_i\\ X& +n⟶{}_3^7{L}_i+\alpha \\ \alpha & ={}_2^4{H}_e\\ n& {=}^{0}n\end{array}$

$\begin{array}{c}X+{}^{1}n{⟶}_3^{7}Li+{}_2^4{H}_e\\ X\text{must have Atomic mass}=10\end{array}$

$\text{and Atomic no.}=5$

${}_5^{10}X={}_5^{10}B$