Extent of Ferromagnetism is maximum in

Options

A. `Fe`
B. `Ni^(2+)`
C. `Co^(3+)`
D. `Cu^(2+)`

Answer

To determine the extent of ferromagnetism in the given options, we need to analyze the magnetic properties of each element or ion. Ferromagnetism is a phenomenon where certain materials can become permanent magnets or exhibit strong magnetic properties due to the alignment of their magnetic moments.

### Step-by-Step Solution:

1. **Understanding Ferromagnetism**:
- Ferromagnetism occurs in materials that have unpaired electrons, allowing them to align their magnetic moments in the presence of an external magnetic field. The extent of ferromagnetism is often measured by the saturation magnetization (MS).

2. **Analyzing the Options**:
- The options provided are:
- A) Iron (Fe)
- B) Nickel (Ni²⁺)
- C) Cobalt (Co³⁺)
- D) Copper (Cu²⁺)

3. **Identifying the Magnetic Moments**:
- Iron (Fe) is known for its strong ferromagnetic properties.
- Nickel (Ni²⁺) and Cobalt (Co³⁺) also exhibit ferromagnetism but to a lesser extent compared to iron.
- Copper (Cu²⁺) is generally not ferromagnetic as it has a filled d-orbital configuration.

4. **Comparing Saturation Magnetization (MS)**:
- The saturation magnetization values for the relevant ions are:
- Iron (Fe): MS = 1,707 A/m
- Cobalt (Co): MS = 1,400 A/m
- Nickel (Ni): MS = 485 A/m
- From this comparison, it is clear that iron has the highest saturation magnetization.

5. **Conclusion**:
- Based on the analysis, the extent of ferromagnetism is maximum in **Iron (Fe)**.

### Final Answer:
The extent of ferromagnetism is maximum in **Iron (Fe)**.

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