a
Species must not contain single unpaired

\({O}_{2}^{+} \rightarrow \sigma_{1 {~s}}^{2}<\sigma_{1 {~s}}^{*}<\sigma_{2 {~s}}^{2}<\sigma_{2 {~s}}^{*}<\sigma_{2 {pz}}^{2}<\pi_{2 {px}}^{2}=\pi_{2 {py}}^{2}<\pi_{2 {px}}^{*}=\pi_{2 {py}}^{*}\)

unpaired \({e}^{-}=1 \ldots \mu=1.73\, {BM}\)

\((1)\) \({Cu}^{+} {I}^{-} {Cu}+\rightarrow[{Ar}] 3 {~d}^{10} \therefore\) unpaired \({e}^{-}=0\)

\({I}^{-} \rightarrow[{Xe}] \therefore\) unpaired \({e}^{-}=0\)

therefore \(\mu=0\)

\(3.\) \(\left[{Cu}\left({NH}_{3}\right)_{4}\right] {Cl}_{2}\)

\({Cu} \rightarrow[{A}] 3 {~d}^{3} \therefore\) unpaired \(=1 \quad \therefore \mu=1.73 \,{BM}\)

\(4.\) \({O}_{2}^{-} \rightarrow {d}\)

\(\sigma_{1 {~s}}^{2}<\sigma_{1 {~s}}^{* 2}<\sigma_{2 {~s}}^{2}<\sigma_{2 {~s}}^{* 2}<\sigma_{2 {px}}^{2}<\pi_{2 {px}}^{2}=\pi_{2 {py}}^{2}<\pi_{2 {px}}^{*_{1}}=\pi_{2 {py}}^{*}\)

\(\left(11 {e}^{-}\right)\)

\(\therefore\) unpaired \(\quad \therefore \mu=1.73\, {BM}\)