JEE Main · 2021 · 27 Aug 2021 · Shift 1 · Solid State

A diamagnetic solid has all its electrons paired and is repelled by a magnetic field; $\mathrm{NaCl}$, built from closed-shell ions, is diamagnetic. Paramagnetism comes from unpaired electrons, and ${\mathrm{O}}_2$ has two unpaired electrons in its ${\pi }^{\ast }$ orbitals, so it is paramagnetic. In an antiferromagnetic solid equal and opposite moments on neighbouring sites cancel completely, as in $\mathrm{MnO}$. In a ferrimagnetic solid the opposing moments are unequal and leave a net moment, as in $\mathrm{F}{\mathrm{e}}_3{\mathrm{O}}_4$. Thus diamagnetism goes with $\mathrm{NaCl}$, ferrimagnetism with $\mathrm{F}{\mathrm{e}}_3{\mathrm{O}}_4$, paramagnetism with ${\mathrm{O}}_2$ and antiferromagnetism with $\mathrm{MnO}$.