(a) Sketch the molecular orbitals of the H2- 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 H2-.
(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 H2- ion to be stable? Explain.