Which of the following is largest

Options

A. `Cl^(-)`
B. `S^(2-)`
C. `Na^(+)`
D. `F^(-)`

Explanation

To determine which of the given ions is the largest, we need to compare the sizes of the ions based on their electron configurations and the number of protons in their nuclei.

### Step-by-Step Solution:

1. **Identify the Ions**: We have three ions to compare: Sulfur (S²⁻), Chlorine (Cl⁻), and another Chlorine (Cl⁻).

2. **Determine the Atomic Numbers**:
- Sulfur (S) has an atomic number of 16.
- Chlorine (Cl) has an atomic number of 17.

3. **Calculate the Number of Protons and Electrons**:
- For Sulfur (S²⁻):
- Protons = 16 (since atomic number is 16)
- Electrons = 16 + 2 = 18 (gains 2 electrons)
- For Chlorine (Cl⁻):
- Protons = 17 (since atomic number is 17)
- Electrons = 17 + 1 = 18 (gains 1 electron)

4. **Compare the Ions**:
- Both S²⁻ and Cl⁻ have 18 electrons. However, the number of protons is different:
- Sulfur (S²⁻) has 16 protons.
- Chlorine (Cl⁻) has 17 protons.

5. **Analyze the Effect of Protons on Size**:
- The size of an ion is influenced by the nuclear charge (number of protons). More protons mean a stronger attraction to the electrons, which pulls the electron cloud closer to the nucleus, resulting in a smaller ion.
- Since S²⁻ has fewer protons (16) compared to Cl⁻ (17), the attraction to the electrons in S²⁻ is weaker, leading to a larger ionic size.

6. **Conclusion**:
- Therefore, among the given ions, S²⁻ is the largest ion.

### Final Answer:
The largest ion among the given options is **S²⁻** (option number 2).

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