Question

According to molecular orbital theory, which of the following will not be a viable molecule ?
(1) He₂⁺ (2) H₂^- (3)  2 H₂^2- (4) ​He₂²⁺

Answer 1

Ans. (3)

The electronic configuration of H₂ ^2Θ is ⇒ σ1s²,(σ*1s²)

Hence   H₂ ^2Θdoes not exist, due to zero bond order

Answer 2

H₂^2- 4e– = σ 1s², σ^∗ 1s²
B.O. = (2-2)/2 = 0
∴ It does not exist as B.O. is zero