(a) Sketch the molecular orbitals of the \(\mathrm{H}_{2}{ }^{-}\)ion and draw
its energy-level diagram. (b) Write the electron configuration of the ion in
terms of its MOs. (c) Calculate the bond order in \(\mathrm{H}_{2}^{-}\). (d)
Suppose that the ion is excited by light, so that an electron moves from a
lower-energy to a higher-energy molecular orbital. Would you expect the
excited-state \(\mathrm{H}_{2}^{-}\)ion to be stable? (e) Which of the following
statements about part (d) is correct: (i) The light excites an electron from a
bonding orbital to an antibonding orbital, (ii) The light excites an electron
from an antibonding orbital to a bonding orbital, or (iii) In the excited
state there are more bonding electrons than antibonding electrons?