The general configuration of transition element is

Options

A. `(n-1)d^(1-5)`
B. `(n-1)d^(1-10)ns^(1)`
C. `(n-1)d^(1-10)ns^(1-2)`
D. `ns^(2)(n-1)d^(10)`

Answer

To determine the general electronic configuration of transition elements, we can follow these steps:

### Step 1: Identify the Transition Elements
Transition elements are defined as the d-block elements in the periodic table. These elements are characterized by the presence of d electrons in their electron configuration.

### Step 2: Understand the General Electronic Configuration
The general electronic configuration for transition elements can be expressed as:
\[ \text{(n-1)d}^{1-10} \text{ns}^{0-2} \]
Where:
- \( n \) is the principal quantum number of the outermost shell.
- \( (n-1)d \) represents the d subshell, which can hold up to 10 electrons.
- \( ns \) represents the s subshell, which can hold up to 2 electrons.

### Step 3: Examples of Transition Elements
1. **Chromium (Cr)**:
- Atomic number: 24
- Electronic configuration: \( [Ar] 4s^1 3d^5 \)
- This shows that for chromium, the configuration deviates slightly from the expected due to stability reasons.

2. **Iron (Fe)**:
- Atomic number: 26
- Electronic configuration: \( [Ar] 4s^2 3d^6 \)
- Here, iron follows the general configuration without deviation.

### Step 4: Conclusion
From the analysis, we can conclude that the general electronic configuration of transition elements is:
\[ \text{(n-1)d}^{1-10} \text{ns}^{0-2} \]

### Final Answer
Thus, the correct answer is:
**N-1, D (from 1 to 10), N-S (from 0 to 2)**.

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