Question

Of the three isobars ${}_{48}^{114}\text{Cd}{}_{49}^{114}\text{In}$ and ${}_{50}^{114}\text{Sn}$
Which is likely to be radioactive and why ?

• A. ${}_{49}^{114}\text{In}$, odd number of nucleons
• B. ${}_{48}^{114}\text{Cd}$, even number of nucleons
• C. ${}_{50}^{114}\text{Sn}$ , even number of nucleons
• D. None of these

Answer 1

The correct option is A ${}_{49}^{114}\text{In}$, odd number of nucleons

Ans is A
${}^{114}Cd$ and ${}^{114}Sn$ we have even number of electrons. This means that all the electrons are paired and hence the structure is stable
but in case of ${}^{114}In$ the last electron will be single hence the structure of atom will be less stable than that of atom with even electrons.