If the magnetic moment of a dioxygen species is 1.73 B.M, it may be :

Magnetic moment = 1.73 BM <br><br>$\therefore$ Unpaired electron = 1 <br><br>(1) $O_2$ has 16 electrons. <br><br>Moleculer orbital configuration of $O_2$ is <br><br>$${\sigma _{1{s^2}}}\,\sigma _{1{s^2}}^ * \,\,{\sigma _{2{s^2}}}\,\,\sigma _{2{s^2}}^ * \,\,{\sigma _{2p_z^2}}\,\,{\pi _{2p_x^2}}\,= \,{\pi _{2p_y^2}}\,\pi _{2p_x^1}^ * = \,\,\pi _{2p_y^1}^ * $$ <br><br>Here 2 unpaired electron present. <br><br>(2)&nbsp;&nbsp; $O_2^{+}$ has 15 electrons. <br><br>Moleculer orbital configuration of $O_2^{+}$ is <br><br>$${\sigma _{1{s^2}}}\,\sigma _{1{s^2}}^ * \,\,{\sigma _{2{s^2}}}\,\,\sigma _{2{s^2}}^ * \,\,{\sigma _{2p_z^2}}\,\,{\pi _{2p_x^2}}\,= \,{\pi _{2p_y^2}}\,\pi _{2p_x^1}^ * = \,\,\pi _{2p_y^0}^ * $$ <br><br>Here 1 unpaired electron present. <br><br>(3)&nbsp;&nbsp; $O_2^{-}$ has 17 electrons. <br><br>Moleculer orbital configuration of $O_2^{-}$ is <br><br>$${\sigma _{1{s^2}}}\,\sigma _{1{s^2}}^ * \,\,{\sigma _{2{s^2}}}\,\,\sigma _{2{s^2}}^ * \,\,{\sigma _{2p_z^2}}\,\,{\pi _{2p_x^2}}\,= \,{\pi _{2p_y^2}}\,\pi _{2p_x^2}^ * = \,\,\pi _{2p_y^1}^ * $$ <br><br>Here 1 unpaired electron present. <br><br>Hence $O_2^{-}$ &amp; $O_2^{+}$ have one unpaired electron.