Every substance has some magnetic properties associated with it. The origin of these properties lies in the electrons. Each electron in an atom behaves like a tiny magnet. Its magnetic moment originates from two types of motions.

(i) Its orbital motion around the nucleus and

(ii) Its spin around its own axis.

Electron being a charged particle and undergoing these motions can be considered as a small loop of current which possesses a magnetic moment. Thus, each electron has a permanent spin and an orbital magnetic moment associated with it. Magnitude of this magnetic moment is very small and is measured in the unit called Bohr magneton, µB. It is equal to 9.27 × 10^–24 Am². On the basis of their magnetic properties, substances can be classified into five categories:

(i) Paramagnetic

(ii) Diamagnetic

(iii) Ferromagnetic

(iv) Antiferromagnetic and

(v) Ferrimagnetic.

Which of the following substances possess above alignments?

Diamagnetic

Diamagnetism: Diamagnetic substances are weakly repelled by a magnetic field. H₂O, NaCl and C₆H₆ are some examples of such substances. They are weakly magnetised in a magnetic field in opposite direction. Diamagnetism is shown by those substances in which all the electrons are paired and there are no unpaired electrons. Pairing of electrons cancels their magnetic moments and they lose their magnetic character.