Problem 1
Why does an electron shared by two nuclei have a lower potential energy than an electron on a single atom? Why does an electron shared by two nuclei have a lower kinetic energy than an electron on a single atom? How does this sharing result in a stable molecule? How can this affect be measured experimentally?
Problem 2
Explain why the bond in an \(H_{2}\) molecule is almost twice as strong as the bond in the \(H_{2}^{+}\) ion. Explain why the \(H_{2}\) bond is less than twice as strong as the \(H_{2}^{+}\) bond.
Problem 3
\(B e_{2}\) is not a stable molecule. What information can we determine from this observation about the energies of molecular orbitals?
Problem 4
Less energy is required to remove an electron from an \(F_{2}\) molecule than to remove an electron from an \(\mathrm{F}\) atom. Therefore, the energy of that electron is higher in the molecule than in the atom. Explain why, nevertheless, \(F_{2}\) is a stable molecule, i.e., the energy of an \(F_{2}\) molecule is less than the energy of two F atoms.
Problem 6
Calculate the bond orders of the following molecules and predict which molecule in each pair has the stronger bond: a. \(C_{2}\) or \(C_{2}^{+}\) b. \(B_{2}\) or \(B_{2}^{+}\) c. \(F_{2}\) or \(F_{2}^{-}\) d. \(O_{2}\) or \(O_{2}^{+}\)
Problem 7
Which of the following diatomic molecules are paramagnetic: \(\mathrm{CO}, \mathrm{Cl}_{2}, \mathrm{NO}, \mathrm{N}_{2} ?\)
Problem 8
\(B_{2}\) is observed to be paramagnetic. Using this information, draw an appropriate molecular orbital energy level diagram for \(B_{2}\).
