Be sure to answer all parts. Use MO diagrams and the bond orders you obtain from them to answer the following questions. (a) Is O2 - stable? Yes No (b) Is O2 - paramagnetic? Yes No (c) What is the outer (valence) electron configuration of O2-? (σ1s) 2 (σ*1s) 2 (σ2s) 2 (σ*2s) 2 (σ2p) 2 (π2p) 2 (π2p) 2 (π*2p) 2 (π*2p) 1 (σ2s) 2 (σ*2s) 2 (σ2p) 2 (π2p) 2 (π2p) 2 (π*2p) 2 (π*2p) 1 (σ1s) 2 (σ*1s) 2 (σ2s) 2 (π2p) 2 (π2p) 2 (π*2p) 2 (π*2p) 1 (σ2s) 2 (σ*2s) 2 (σ2p) 2 (σ2p) 2 (π2p) 2 (π*2p) 2 (π*2p) 1

a) yes b) no c) (σ2s) 2 (σ*2s) 2 (σ2p) 2 (σ2p) 2 (π2p) 2 (π*2p) 2 (π*2p) 1

Explanation:

The stability of a molecule depends on the number of bonding and antibonding electrons present. In the O22 - ion, there are 10 bonding and 8 antibonding electrons. From the formula bond order = bonding electrons - antibonding electrons/2, we realize that the bond order is 1 meaning that the ion is stable. All the electrons are paired so it isn't paramagnetic. The valence shell is ordered as shown in the answer.