Chemistry - Solid State Question with Solution | TestHub

The magnetic properties of the given substances are as follows:

$\text{NaCl}$ is a diamagnetic substance because all its electrons are paired.

${\text{C}}_6{\text{H}}_6$ (benzene) is also a diamagnetic substance.

${\text{O}}_2$ is a paramagnetic substance due to the presence of two unpaired electrons in its anti-bonding molecular orbitals.

$\text{Gd}$ (Gadolinium) is a ferromagnetic substance, along with other metals like iron, cobalt, and nickel.

Answer: $\text{Gd}$.