Which species has the maximum number of lone pair of electrons on the central atom ?

Options

A. ` [ClO_3]^(-)`
B. ` XeF_4`
C. ` SF_4`
D. `[I_3]^(-)`

Explanation

To determine which species has the maximum number of lone pairs of electrons on the central atom, we will analyze each option step by step.

### Step 1: Analyze ClO3⁻ (Chlorate Ion)
- The central atom is chlorine (Cl).
- Chlorine has 7 valence electrons.
- In ClO3⁻, there are 3 oxygen atoms bonded to chlorine.
- Each oxygen atom forms a single bond with chlorine, using 3 of chlorine's valence electrons.
- After forming these bonds, we have 4 electrons remaining (7 - 3 = 4).
- These 4 electrons can form 2 lone pairs.
- **Lone pairs on Cl: 1 lone pair.**

### Step 2: Analyze XeF4 (Xenon Tetrafluoride)
- The central atom is xenon (Xe).
- Xenon has 8 valence electrons.
- In XeF4, there are 4 fluorine atoms bonded to xenon.
- Each fluorine atom forms a single bond with xenon, using 4 of xenon's valence electrons.
- After forming these bonds, we have 4 electrons remaining (8 - 4 = 4).
- These 4 electrons can form 2 lone pairs.
- **Lone pairs on Xe: 2 lone pairs.**

### Step 3: Analyze SF4 (Sulfur Tetrafluoride)
- The central atom is sulfur (S).
- Sulfur has 6 valence electrons.
- In SF4, there are 4 fluorine atoms bonded to sulfur.
- Each fluorine atom forms a single bond with sulfur, using 4 of sulfur's valence electrons.
- After forming these bonds, we have 2 electrons remaining (6 - 4 = 2).
- These 2 electrons can form 1 lone pair.
- **Lone pairs on S: 1 lone pair.**

### Step 4: Analyze I3⁻ (Iodide Ion)
- The central atom is iodine (I).
- Iodine has 7 valence electrons.
- In I3⁻, there are 2 iodine atoms bonded to a central iodine atom, and there is an extra electron due to the negative charge.
- This gives us a total of 8 valence electrons (7 + 1).
- The two iodine atoms form bonds with the central iodine, using 2 of its valence electrons.
- After forming these bonds, we have 6 electrons remaining (8 - 2 = 6).
- These 6 electrons can form 3 lone pairs.
- **Lone pairs on I: 3 lone pairs.**

### Conclusion
After analyzing all the species:
- ClO3⁻ has 1 lone pair.
- XeF4 has 2 lone pairs.
- SF4 has 1 lone pair.
- I3⁻ has 3 lone pairs.

The species with the maximum number of lone pairs on the central atom is **I3⁻**, which has **3 lone pairs**.

### Final Answer
**D. I3⁻ (Iodide Ion) has the maximum number of lone pairs on the central atom.**

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