Which of the following ions has an (18 + 2) electronic configuration ?

Options

A. `Cu^(+)`
B. `Fe^(3+)`
C. `Pb^(2+)`
D. `Xe^(2+)`

Explanation

To determine which of the following ions has an (18 + 2) electronic configuration, we need to analyze the electronic configurations of the given ions and see which one has 18 electrons in the inner shell and 2 electrons in the outermost shell (valence shell).

### Step-by-Step Solution:

1. **Understanding (18 + 2) Configuration**:
- The notation (18 + 2) means that there are 18 electrons in the inner shells and 2 electrons in the outermost shell (valence shell).

2. **Analyzing Each Ion**:
- We will go through each option one by one to find the correct electronic configuration.

3. **Option 1: Copper Ion (Cu⁺)**:
- The electronic configuration of neutral copper (Cu) is:
\[ \text{Cu: } [\text{Ar}] 3d^{10} 4s^1 \]
- For Cu⁺, we remove one electron from the 4s orbital:
\[ \text{Cu}^+: [\text{Ar}] 3d^{10} \]
- Here, there are no electrons in the valence shell (4s), so this option is incorrect.

4. **Option 2: Iron Ion (Fe³⁺)**:
- The electronic configuration of neutral iron (Fe) is:
\[ \text{Fe: } [\text{Ar}] 3d^6 4s^2 \]
- For Fe³⁺, we remove two electrons (first from 4s, then from 3d):
\[ \text{Fe}^{3+}: [\text{Ar}] 3d^5 \]
- Again, there are no electrons in the valence shell, so this option is also incorrect.

5. **Option 3: Lead Ion (Pb²⁺)**:
- The electronic configuration of neutral lead (Pb) is:
\[ \text{Pb: } [\text{Xe}] 4f^{14} 5d^{10} 6s^2 6p^2 \]
- For Pb²⁺, we remove two electrons from the 6p orbital:
\[ \text{Pb}^{2+}: [\text{Xe}] 4f^{14} 5d^{10} 6s^2 \]
- Here, there are 2 electrons in the valence shell (6s), which matches our requirement of (18 + 2). Thus, this option is correct.

6. **Option 4: Xenon Ion (Xe²⁺)**:
- The electronic configuration of neutral xenon (Xe) is:
\[ \text{Xe: } [\text{Kr}] 4d^{10} 5s^2 5p^6 \]
- For Xe²⁺, we remove two electrons from the 5p orbital:
\[ \text{Xe}^{2+}: [\text{Kr}] 4d^{10} 5s^2 5p^4 \]
- In this case, there are 4 electrons in the valence shell (5s and 5p), so this option is incorrect.

### Conclusion:
The ion that has an (18 + 2) electronic configuration is **Lead Ion (Pb²⁺)**.