Explain paramagnetism and diamagnetism. Write a note on ferromagnetism. Explain antiferromagnetism.

(N/A) Paramagnetism: Substances that are weakly attracted by a magnetic field are called paramagnetic substances. They are magnetized in a magnetic field in the same direction and lose their magnetism in the absence of the magnetic field. This is due to the presence of one or more unpaired electrons.
Diamagnetism: Substances that are weakly repelled by a magnetic field are called diamagnetic substances. They are weakly magnetized in a magnetic field in the opposite direction. This is due to the presence of only paired electrons.
Ferromagnetism: Substances that are attracted strongly by a magnetic field and retain magnetism even in the absence of magnetic fields are called ferromagnetic substances. In solid state,the metal ions are grouped together into small regions called domains. Each domain acts as a tiny magnet. In an unmagnetized piece,domains are randomly oriented,cancelling their magnetic moments. When placed in a magnetic field,all domains orient in the direction of the field,producing a strong magnetic effect. This ordering persists even after the field is removed,making them permanent magnets.
Antiferromagnetism: Substances that have zero net magnetic moment despite having unpaired electrons are called antiferromagnetic substances. In these,the domain structure is similar to ferromagnetic substances,but the domains are oriented in opposite directions,cancelling each other's magnetic moments. Examples: $MnO$,$Fe_{2}O_{3}$,$V_{2}O_{3}$.