Question: In which of the following pairs of molecules/ions, both the species are not likely to exist ?
$\mathrm{H}_{2}^{+}, \mathrm{He}_{2}^{2-}$
$\mathrm{H}_{2}^{-}, \mathrm{He}_{2}^{2-}$
$\mathrm{H}_{2}^{2+}, \mathrm{He}_{2}$
$\mathrm{H}_{2}^{-}, \mathrm{He}_{2}^{2+}$
Correct Option: , 3
Solution:
