The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.

Options

A. `3d^(7)`
B. `3d^(5)`
C. `3d^(8)`
D. `3d^(2)`

Explanation

To determine the configuration of a transition element that shows the highest magnetic moment, we need to follow these steps:

### Step 1: Understand the Concept of Magnetic Moment
The magnetic moment of an element is influenced by the number of unpaired electrons present in its electronic configuration. The formula for calculating the magnetic moment (μ) in Bohr magnetons (BM) is given by:

\[ \mu = \sqrt{n(n + 2)} \]

where \( n \) is the number of unpaired electrons.

### Step 2: Identify the Electronic Configurations
We need to analyze the electronic configurations of various transition elements. The common configurations we will consider are:

- D2: \( [Ar] 3d^2 \)
- D5: \( [Ar] 3d^5 \)
- D7: \( [Ar] 3d^7 \)
- D8: \( [Ar] 3d^8 \)

### Step 3: Determine the Number of Unpaired Electrons
Now, we will find the number of unpaired electrons in each configuration:

- **D2 Configuration**:
- Configuration: \( 3d^2 \)
- Unpaired Electrons: 2 (both electrons are unpaired)

- **D5 Configuration**:
- Configuration: \( 3d^5 \)
- Unpaired Electrons: 5 (all five electrons are unpaired)

- **D7 Configuration**:
- Configuration: \( 3d^7 \)
- Unpaired Electrons: 3 (there are 3 unpaired electrons)

- **D8 Configuration**:
- Configuration: \( 3d^8 \)
- Unpaired Electrons: 2 (there are 2 unpaired electrons)

### Step 4: Compare the Number of Unpaired Electrons
From the analysis above, we can summarize the number of unpaired electrons:

- D2: 2 unpaired electrons
- D5: 5 unpaired electrons
- D7: 3 unpaired electrons
- D8: 2 unpaired electrons

The configuration with the highest number of unpaired electrons is D5, which has 5 unpaired electrons.

### Step 5: Calculate the Magnetic Moment for D5 Configuration
Using the formula for magnetic moment:

\[ \mu = \sqrt{n(n + 2)} = \sqrt{5(5 + 2)} = \sqrt{5 \times 7} = \sqrt{35} \approx 5.92 \text{ BM} \]

### Conclusion
The configuration of the transition element that shows the highest magnetic moment is the D5 configuration, which has 5 unpaired electrons and a magnetic moment of approximately 5.92 Bohr magnetons.

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