Question

An excited electronic state of He₂ does not have

• A. Equal bonding and antibonding electrons
• B. More bonding than antibonding electrons
• C. Stability towards dissociation into atoms
• D. Preponderence of electrons between the nuclei

Answer 1

Answer: (A)

Equal bonding and antibonding electrons

Answer 2

The excited state configuration of He₂ is $\sigma_{1s}^{2}$ ${\sigma^{*}}_{1s}^{1}$ $\sigma_{2s}^{1}$; BO = $\frac{1}{2}$ (3 – 1) = 1 ; therefore excited He₂ is stable toward dissociation into atoms.