Match List-I with List-II:List-IList-II(A) Diamagnetic solid(I) CrO₂(B) Ferromagnetic solid(II) Fe₃O₄(C) Antiferromagnetic solid(III) NaCl(D) Ferrimagnetic solid(IV) MnOChoose the correct answer from the options given below:

Question

Prepp Team · Accepted Answer

Understanding Magnetic Properties of Solids

Solids can exhibit different magnetic behaviors depending on the arrangement and interactions of electron spins within their atoms or ions. When placed in an external magnetic field, solids respond in various ways, leading to classifications like diamagnetic, paramagnetic, ferromagnetic, antiferromagnetic, and ferrimagnetic solids.

Let's analyze the given list of solids and match them with their respective magnetic properties.

Types of Magnetic Solids and Examples

Here's a breakdown of the different types of magnetic solids mentioned in List-I and their corresponding examples from List-II:

Diamagnetic Solids:
These substances are weakly repelled by an external magnetic field. They have no unpaired electrons in their atoms or molecules. When a magnetic field is applied, a small magnetic moment is induced in the opposite direction of the applied field.

Example from List-II: NaCl (Sodium Chloride)

Explanation: NaCl is an ionic compound. Both Na⁺ and Cl⁻ ions have complete electron shells (like Noble gases), meaning they have no unpaired electrons. Therefore, NaCl is a diamagnetic solid.
Ferromagnetic Solids:
These solids are strongly attracted by an external magnetic field and can retain their magnetism even after the field is removed (permanent magnetism). They have unpaired electrons, and the magnetic moments align parallel to each other in large regions called domains. In the presence of a field, these domains align, resulting in a strong net magnetic moment.

Example from List-II: CrO₂ (Chromium Dioxide)

Explanation: While common ferromagnetic examples are Fe, Co, Ni, CrO₂ is a well-known example of a ferromagnetic oxide. Its structure and electronic configuration lead to strong positive exchange interactions between magnetic moments, resulting in parallel alignment and ferromagnetism at room temperature.
Antiferromagnetic Solids:
These solids are weakly attracted by an external magnetic field or sometimes appear diamagnetic. They have unpaired electrons, but the magnetic moments in adjacent atoms or ions align in an antiparallel fashion and cancel each other out, resulting in a net magnetic moment of zero.

Example from List-II: MnO (Manganese(II) Oxide)

Explanation: In MnO, the Mn²⁺ ions have unpaired electrons. Below a certain temperature (Neel temperature), the magnetic moments of neighboring Mn²⁺ ions align in opposite directions (antiparallel) with equal magnitude, leading to a net zero magnetic moment and thus antiferromagnetism.
Ferrimagnetic Solids:
These solids are attracted by an external magnetic field but less strongly than ferromagnetic substances. They also have unpaired electrons, and the magnetic moments in adjacent atoms or ions align antiparallel, but the moments are of unequal magnitudes. This results in a non-zero net magnetic moment.

Example from List-II: Fe₃O₄ (Iron(II,III) Oxide or Magnetite)

Explanation: Fe₃O₄ contains both Fe²⁺ and Fe³⁺ ions in its crystal lattice. The magnetic moments of these ions align antiparallel to each other, but since there are unequal numbers of ions or unequal magnitudes of moments aligned in opposite directions, there is a net magnetic moment. This makes Fe₃O₄ a ferrimagnetic solid.

Matching List-I with List-II

Based on the properties and examples discussed:

(A) Diamagnetic solid matches with (III) NaCl.
(B) Ferromagnetic solid matches with (I) CrO₂.
(C) Antiferromagnetic solid matches with (IV) MnO.
(D) Ferrimagnetic solid matches with (II) Fe₃O₄.

This corresponds to the combination (A)-(III), (B)-(I), (C)-(IV), (D)-(II).

Magnetic Solid Classification Summary

Here is a table summarizing the classifications and examples:

List-I (Magnetic Solid Type)	List-II (Example)
(A) Diamagnetic solid	(III) NaCl
(B) Ferromagnetic solid	(I) CrO₂
(C) Antiferromagnetic solid	(IV) MnO
(D) Ferrimagnetic solid	(II) Fe₃O₄

Revision Table: Magnetic Properties of Solids

Property Type	Electron Spins	Response to Field	Net Magnetic Moment	Example
Diamagnetic	Paired	Weak repulsion	Zero (induced opposite moment)	NaCl, H₂O, N₂
Paramagnetic	Unpaired, Random alignment	Weak attraction	Zero (becomes non-zero in field)	O₂, Cu²⁺, Al
Ferromagnetic	Unpaired, Parallel alignment (domains)	Strong attraction, retains magnetism	Large	Fe, Co, Ni, CrO₂
Antiferromagnetic	Unpaired, Antiparallel alignment (equal moments)	Weak attraction/repulsion	Zero	MnO, FeO
Ferrimagnetic	Unpaired, Antiparallel alignment (unequal moments)	Attraction (weaker than ferromagnetic)	Non-zero (resultant)	Fe₃O₄ (Magnetite), Ferrites

Additional Information on Magnetic Solids

Magnetic properties of solids are determined by the behavior of electrons, particularly their spin and orbital angular momentum. Key concepts related to magnetism include:

Magnetic Domains: In ferromagnetic and ferrimagnetic materials, regions exist where magnetic moments are aligned. These are called domains. When an external field is applied, these domains grow or reorient, leading to bulk magnetism.
Curie Temperature (T_C): For ferromagnetic and ferrimagnetic substances, there is a critical temperature above which they lose their strong magnetism and become paramagnetic.
Neel Temperature (T_N): For antiferromagnetic substances, there is a critical temperature above which the antiparallel alignment breaks down, and they become paramagnetic.
Unpaired Electrons: The presence of unpaired electrons is crucial for paramagnetic, ferromagnetic, antiferromagnetic, and ferrimagnetic behavior, as each unpaired electron acts like a tiny magnet. Diamagnetism arises from the orbital motion of all electrons, regardless of pairing.