The ion having a noble gas electronic configuration is

Options

A. `Se^(2-)`
B. `Fe^(3+)`
C. `Cr^(3+)`
D. `Cu^(+)`

Answer

To determine which ion has a noble gas electronic configuration, we will analyze the electronic configurations of the given options.

### Step-by-Step Solution:

1. **Identify the Electronic Configuration of Each Ion:**
- **Option A: Selenium (Se²⁻)**
- Selenium has an atomic number of 34. Its ground state electronic configuration is:
\[ \text{Se: } [\text{Ar}] 4s^2 3d^{10} 4p^4 \]
- When it gains 2 electrons to form Se²⁻, the configuration becomes:
\[ \text{Se}^{2-}: [\text{Ar}] 4s^2 3d^{10} 4p^6 \]
- This configuration corresponds to the noble gas Krypton (Kr), which has an atomic number of 36.

2. **Option B: Iron (Fe³⁺)**
- Iron has an atomic number of 26. Its ground state electronic configuration is:
\[ \text{Fe: } [\text{Ar}] 4s^2 3d^6 \]
- When it loses 3 electrons to form Fe³⁺, the configuration becomes:
\[ \text{Fe}^{3+}: [\text{Ar}] 3d^5 \]
- This does not correspond to a noble gas configuration.

3. **Option C: Chromium (Cr³⁺)**
- Chromium has an atomic number of 24. Its ground state electronic configuration is:
\[ \text{Cr: } [\text{Ar}] 4s^2 3d^4 \]
- When it loses 3 electrons to form Cr³⁺, the configuration becomes:
\[ \text{Cr}^{3+}: [\text{Ar}] 3d^3 \]
- This does not correspond to a noble gas configuration.

4. **Option D: Copper (Cu⁺)**
- Copper has an atomic number of 29. Its ground state electronic configuration is:
\[ \text{Cu: } [\text{Ar}] 4s^2 3d^{10} \]
- When it loses 1 electron to form Cu⁺, the configuration becomes:
\[ \text{Cu}^{+}: [\text{Ar}] 4s^0 3d^{10} \]
- This configuration does not correspond to a noble gas configuration.

5. **Conclusion:**
- The only ion that has a noble gas electronic configuration is **Selenium (Se²⁻)**, which has the configuration of Krypton.

### Final Answer:
The ion having a noble gas electronic configuration is **Selenium (Se²⁻)**.