(b) $\begin{array}{*{20}{c}}{}&{He_2^ + }&{{H_2}}&{H_2^ + }&{H_2^ – }\\{\sigma (1s)}&{\underline { \uparrow \downarrow } }&{\underline { \uparrow \downarrow } }&{\underline { \uparrow \,} }&{\underline { \uparrow \downarrow } }\\{\mathop \sigma \limits^* (1s)}&{\underline { \uparrow \,} }&{\underline {\,\,\,\,} }&{\underline {\,\,\,\,} }&{\underline { \uparrow \,} }\\{B.O.}&{\frac{1}{2}}&1&{\frac{1}{2}}&{\frac{1}{2}}\\\begin{array}{l}{\rm{Magnetic}}\\{\rm{nature}}\end{array}&{\rm{P}}&{\rm{D}}&{\rm{P}}&{\rm{P}}\end{array}$

$(P =$ Paramagnetic, $D =$ Diamagnetic$)$