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 given ions has an (18 + 2) electronic configuration, we need to analyze the electronic configurations of each ion provided. The (18 + 2) configuration indicates that there are 18 electrons in the inner shell and 2 electrons in the valence shell.

### Step-by-Step Solution:

1. **Identify the Electronic Configuration of Copper (Cu²⁺)**:
- The atomic number of copper is 29, which means it has 29 electrons in its neutral state.
- The electronic configuration of neutral copper is:
\[ [Ar] 3d^{10} 4s^1 \]
- For Cu²⁺, we remove one electron from the 4s orbital:
\[ [Ar] 3d^{10} 4s^0 \]
- This gives us an inner shell count of 18 (from the Argon core) and a valence shell count of 0. So, Cu²⁺ has a configuration of (18 + 0).

2. **Identify the Electronic Configuration of Iron (Fe³⁺)**:
- The atomic number of iron is 26, so it has 26 electrons in its neutral state.
- The electronic configuration of neutral iron is:
\[ [Ar] 3d^6 4s^2 \]
- For Fe³⁺, we remove 3 electrons (2 from 4s and 1 from 3d):
\[ [Ar] 3d^5 4s^0 \]
- This gives us an inner shell count of 18 (from the Argon core) and a valence shell count of 0. So, Fe³⁺ has a configuration of (18 + 0).

3. **Identify the Electronic Configuration of Lead (Pb²⁺)**:
- The atomic number of lead is 82, meaning it has 82 electrons in its neutral state.
- The electronic configuration of neutral lead is:
\[ [Xe] 6s^2 6p^2 \]
- For Pb²⁺, we remove 2 electrons from the 6p orbital:
\[ [Xe] 6s^2 6p^0 \]
- This gives us an inner shell count of 18 (from the Xenon core) and a valence shell count of 2. So, Pb²⁺ has a configuration of (18 + 2).

4. **Identify the Electronic Configuration of Xenon (Xe²⁺)**:
- The atomic number of xenon is 54, so it has 54 electrons in its neutral state.
- The electronic configuration of neutral xenon is:
\[ [Kr] 4s^2 4p^6 \]
- For Xe²⁺, we remove 2 electrons from the 5p orbital:
\[ [Kr] 4s^2 4p^4 \]
- This gives us an inner shell count of 18 (from the Krypton core) and a valence shell count of 6. So, Xe²⁺ has a configuration of (18 + 6).

### Conclusion:
Among the ions analyzed, only **Lead (Pb²⁺)** has an electronic configuration of (18 + 2). Therefore, the correct answer is:

**Answer: Lead (Pb²⁺)**