Which of the following ions has a pseudo-inert-gas configuration?

Options

A. `Zn^(2+)`
B. `Cu^(+)`
C. `Ag^(+)`
D. All of these

Explanation

To determine which of the given ions has a pseudo-inert-gas configuration, we need to understand what a pseudo-inert-gas configuration is. A pseudo-inert-gas configuration occurs when an ion has 18 electrons in its valence shell. Let's analyze each ion provided in the options.

### Step-by-Step Solution:

1. **Understanding Pseudo-Inert-Gas Configuration**:
- A pseudo-inert-gas configuration is characterized by having 18 electrons in the outermost shell (valence shell).

2. **Analyzing the First Ion: Zn²⁺**:
- The electronic configuration of neutral Zinc (Zn) is:
\[ \text{Zn: } [\text{Ar}] 3d^{10} 4s^2 \]
- When Zinc loses two electrons to form Zn²⁺, it loses the two 4s electrons:
\[ \text{Zn}^{2+}: [\text{Ar}] 3d^{10} \]
- The valence shell for Zn²⁺ is the 3d subshell, which contains 10 electrons from 3d and 8 from the filled 3s and 3p orbitals (total = 18). Thus, Zn²⁺ has a pseudo-inert-gas configuration.

3. **Analyzing the Second Ion: Cu⁺**:
- The electronic configuration of neutral Copper (Cu) is:
\[ \text{Cu: } [\text{Ar}] 3d^{10} 4s^1 \]
- When Copper loses one electron to form Cu⁺, it loses the single 4s electron:
\[ \text{Cu}^{+}: [\text{Ar}] 3d^{10} \]
- Similar to Zn²⁺, the valence shell for Cu⁺ also contains 18 electrons (10 from 3d and 8 from 3s and 3p). Thus, Cu⁺ has a pseudo-inert-gas configuration.

4. **Analyzing the Third Ion: Ag⁺**:
- The electronic configuration of neutral Silver (Ag) is:
\[ \text{Ag: } [\text{Kr}] 4d^{10} 5s^2 \]
- When Silver loses one electron to form Ag⁺, it loses one 5s electron:
\[ \text{Ag}^{+}: [\text{Kr}] 4d^{10} \]
- The valence shell for Ag⁺ contains 10 electrons from 4d and 8 from the filled 4s and 4p orbitals (total = 18). Thus, Ag⁺ also has a pseudo-inert-gas configuration.

5. **Conclusion**:
- All three ions (Zn²⁺, Cu⁺, and Ag⁺) have pseudo-inert-gas configurations as they all contain 18 electrons in their valence shells.

### Final Answer:
All of the given ions (Zn²⁺, Cu⁺, and Ag⁺) have a pseudo-inert-gas configuration.