Write three differences between diamagnetic and paramagnetic substances.

Hint: Diamagnetic and paramagnetic materials can be differentiated on the basis of their chemical and physical properties. Paramagnetic materials are attracted by external magnetic fields whereas diamagnetic materials are repelled. Paramagnetic materials have at least one unpaired electron in the system, but diamagnetic materials have all their electrons paired.

Complete step by step solution:
Differences between diamagnetic and paramagnetic are as follows :

Diamagnetic substances:–
1. When a diamagnetic substance is kept in a magnetizing field, then the magnetic field lines will be repelled by the diamagnetic substances.
2. Relative permeability of diamagnetic substance is less than one is ${\mu _r} < 1$
3. The susceptibility of diamagnetic substance is negative.

Paramagnetic substance:-
1. When a paramagnetic substance is kept in an external magnetic field the field lines pass through the paramagnetic substances.
2. Relative permeability of paramagnetic substance is more than one ${\mu _r} < 1$
3. The susceptibility of paramagnetic substance is positive.

Note: The magnetic field created by paramagnetic materials are in the direction of the external magnetic field whereas the magnetic field created by diamagnetic materials are opposing in direction to the external magnetic field. Paramagnetism is a stronger magnetic behaviour exhibited only by selective materials, whereas diamagnetism is a weak magnetic behaviour generally shown by all materials and easily suppressed in the presence of stronger magnetic properties.