In which of the following paris of molecules/ions, both the species are not likely to exist?

Options

A. `H_2^+ , He_2^(2-)`
B. `H_2^- , He_2^(2-)`
C. `H_2^(2+), He_2`
D. `H_2^- , He_2^(2+)`

Answer

C

Explanation

Species having zero or negative bond order do not exist.
`H_2^(2+)` (1+1-2=0) = `sigma1s^2`
Bond order =0
`He_2` (2+2=4) = `sigma1s^2 , sigma**1s^2`
Bond order = `(N_b-N_a)/2 =(2-2)/2 =0`
So, both `H_2^(2+)` and `He_2` do not exist .