Which of the following property is associated with diamagnetic solid substances?

They are weakly repelled by external magnetic field

The correct answer is option 2. They are weakly repelled by external magnetic field.

The property associated with diamagnetic solid substances is that they are weakly repelled by an external magnetic field.

Diamagnetic substances: These materials are characterized by having all their electrons paired. When an external magnetic field is applied, the magnetic moments of the paired electrons tend to align in such a way as to oppose the applied field. This results in a weak repulsion from the magnetic field.

Weakly attracted by external magnetic field: This describes paramagnetic substances, which have unpaired electrons that align with the magnetic field, causing a weak attraction.

Permanent alignment of magnetic moment: This describes ferromagnetic substances, which have a permanent magnetic moment even in the absence of an external magnetic field.

Unequal number of alignments of magnetic moments: This describes ferrimagnetic substances, where magnetic moments align in opposite directions but with unequal magnitudes, resulting in a net magnetic moment.

Therefore, the correct property associated with diamagnetic solid substances is 2. They are weakly repelled by external magnetic field