When sodium and oxygen react, one of the products obtained is sodium peroxide, Na₂O₂. The anion in this compound is the peroxide ion, O₂²⁻. Write the electron configuration for this ion in molecular orbital terms, and draw the electron dot structure.
(a) Compare the ion with the O₂ molecule with respect to the following: magnetic character, net number of σ and π bonds, bond order, and oxygen–oxygen bond length.
(b) Compare the valence bond and MO pictures with regard to the number of σ and π bonds and the bond order.