Fe, Co and Ni are

Options

A. ferrimagnetic materials
B. anti-ferromagnetic materials
C. ferromagnetic materials
D. diamagnetic materials

Answer

To determine whether Iron (Fe), Cobalt (Co), and Nickel (Ni) are ferromagnetic, antiferromagnetic, or diamagnetic, we need to analyze their electronic configurations and the presence of unpaired electrons.

### Step 1: Identify the electronic configurations of Fe, Co, and Ni.
- **Iron (Fe)**: Atomic number = 26
- Electronic configuration: \( [Ar] 3d^6 4s^2 \)

- **Cobalt (Co)**: Atomic number = 27
- Electronic configuration: \( [Ar] 3d^7 4s^2 \)

- **Nickel (Ni)**: Atomic number = 28
- Electronic configuration: \( [Ar] 3d^8 4s^2 \)

### Step 2: Determine the number of unpaired electrons in each element.
- **Iron (Fe)**:
- In \( 3d^6 \), the distribution of electrons is: ↑↓ ↑↓ ↑ ↑ ↑ (4 unpaired electrons).

- **Cobalt (Co)**:
- In \( 3d^7 \), the distribution of electrons is: ↑↓ ↑↓ ↑ ↑ ↑ (3 unpaired electrons).

- **Nickel (Ni)**:
- In \( 3d^8 \), the distribution of electrons is: ↑↓ ↑↓ ↑↓ ↑ (2 unpaired electrons).

### Step 3: Analyze the magnetic properties based on unpaired electrons.
- **Ferromagnetic materials** have unpaired electrons that align in the same direction, resulting in a net magnetic moment.
- **Antiferromagnetic materials** have unpaired electrons that align in opposite directions, canceling each other out.
- **Diamagnetic materials** have all electrons paired, resulting in no net magnetic moment.

### Conclusion:
- Since all three elements (Fe, Co, and Ni) have unpaired electrons:
- Iron (Fe) has 4 unpaired electrons.
- Cobalt (Co) has 3 unpaired electrons.
- Nickel (Ni) has 2 unpaired electrons.

Thus, all three elements are **ferromagnetic** due to the presence of unpaired electrons that contribute to a permanent magnetic moment.

### Final Answer:
**Fe, Co, and Ni are ferromagnetic materials.**