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Question
State briefly the molecular theory of magnetism.
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Solution
- Each molecule of a magnetic substance, whether it is magnetized or unmagnetized, is an independent magnet.
- In a magnetized substance, the molecules are arranged in an order so as to produce an external effect. In this order, all the north poles of the molecules of the magnetized substances point to one direction and all their south poles point to a direction opposite to that to which their north poles points.
- In an unmagnetized substance, the molecules are not arranged in any order, so they neutralize the magnetic forces of each other.
- The molecular theory of magnetism was a considerable step forward but later there came an electrical explanation for the magnetism of atoms.
Atoms consist of negatively charged particles (electrons) that revolve around the positively charged nucleus. Electrical current loops are formed in an atom due to the circulation of these electrons. Each current loop behaves a magnetic dipole and hence produce a magnetic field. Also, electrons are also spinning like tops and this adds further magnetism to the atom.
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