Under normal conditions which of the given electronic configuration is able to from dispositive ion?

Options

A. Br
B. Cl
C. Mg
D. None of these

Answer

To determine which electronic configuration can form a dipositive ion (M²⁺), we need to analyze the electronic configurations of the given elements. A dipositive ion is formed when an atom loses two electrons. Let's evaluate the options step by step.

### Step-by-Step Solution:

1. **Identify the Elements and Their Electronic Configurations**:
- **Bromine (Br)**: Atomic number = 35
- Electronic configuration: \( \text{[Ar]} 4s^2 3d^{10} 4p^5 \)
- **Chlorine (Cl)**: Atomic number = 17
- Electronic configuration: \( \text{[Ne]} 3s^2 3p^5 \)
- **Magnesium (Mg)**: Atomic number = 12
- Electronic configuration: \( \text{[Ne]} 3s^2 \)

2. **Analyze Bromine**:
- Bromine has 7 valence electrons (4s² 4p⁵).
- If it loses 2 electrons, it would have the configuration \( \text{[Ar]} 4s^2 3d^{10} 4p^3 \).
- However, bromine prefers to gain an electron to achieve a stable noble gas configuration (Krypton), hence it does not form a dipositive ion.

3. **Analyze Chlorine**:
- Chlorine has 7 valence electrons (3s² 3p⁵).
- If it loses 2 electrons, it would have the configuration \( \text{[Ne]} 3s^2 3p^3 \).
- Like bromine, chlorine prefers to gain an electron to achieve a stable noble gas configuration (Argon), so it does not form a dipositive ion.

4. **Analyze Magnesium**:
- Magnesium has 2 valence electrons (3s²).
- If it loses 2 electrons, it would have the configuration \( \text{[Ne]} \), which is a stable noble gas configuration.
- Therefore, magnesium readily forms a dipositive ion (Mg²⁺) by losing its two valence electrons.

5. **Conclusion**:
- Among the given options, only magnesium can form a dipositive ion (Mg²⁺). Therefore, the correct answer is **Magnesium (Mg)**.

### Final Answer:
**Magnesium (Mg) is able to form a dipositive ion (Mg²⁺).**