Which of the following is ferromagnetic?

Options

A. Calcium metal
B. Iron metal
C. Sodium metal
D. Zinc metal

Answer

To determine which of the given options is ferromagnetic, we need to understand the characteristics of ferromagnetic materials and analyze each option accordingly.

### Step-by-Step Solution:

1. **Understanding Ferromagnetism**:
- Ferromagnetic materials exhibit strong magnetism. They can retain their magnetic properties even in the absence of an external magnetic field. This is due to the alignment of magnetic moments of atoms or ions in the material.

2. **Analyzing the Options**:
- We have four options to consider: Calcium (Ca), Iron (Fe), Sodium (Na), and Zinc (Zn).

3. **Calcium (Ca)**:
- Calcium is an alkaline earth metal and does not exhibit ferromagnetism. It has a relatively simple electron configuration and does not have unpaired electrons that contribute to magnetic properties.

4. **Iron (Fe)**:
- Iron is a transition metal with a significant number of unpaired electrons in its d-orbitals. This allows it to exhibit strong ferromagnetic properties. Iron is well-known for its ferromagnetic behavior.

5. **Sodium (Na)**:
- Sodium is an alkali metal and also does not exhibit ferromagnetism. It has a single unpaired electron, but this is not sufficient for ferromagnetic behavior.

6. **Zinc (Zn)**:
- Zinc is another transition metal, but it has a full d-subshell (d10 configuration) and does not have unpaired electrons. Therefore, it does not exhibit ferromagnetism.

7. **Conclusion**:
- Among the options provided, **Iron (Fe)** is the only ferromagnetic material.

### Final Answer:
The ferromagnetic material among the given options is **Iron (Fe)**.

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