In how many following species , the central atoms have two lone pairs of electrons ?
`{:(XeF_4,XeF_5^-,F_2SeO_2),(XeF_3^(+),XeOF_4,CIOF_3),(ICl_4^(-), SCl_2, OSF_4):}`

Explanation

To determine how many of the given species have central atoms with two lone pairs of electrons, we will analyze each species one by one.

### Step-by-Step Solution:

1. **Identify the species**: The species given are:
- XeF₄
- XeF₅⁻
- F₂SeO₂
- XeF₃⁺
- ICl₄⁻
- XeOF₄
- ClOF₃
- SCl₂
- OSF₄

2. **Draw the Lewis structure and count lone pairs for each species**:

- **XeF₄**:
- Central atom: Xenon (Xe)
- Structure: Xe is bonded to 4 fluorine atoms and has 2 lone pairs.
- **Lone pairs**: 2

- **XeF₅⁻**:
- Central atom: Xenon (Xe)
- Structure: Xe is bonded to 5 fluorine atoms and has 2 lone pairs.
- **Lone pairs**: 2

- **F₂SeO₂**:
- Central atom: Selenium (Se)
- Structure: Se is bonded to 2 fluorine atoms and has 0 lone pairs (double bonds with O).
- **Lone pairs**: 0

- **XeF₃⁺**:
- Central atom: Xenon (Xe)
- Structure: Xe is bonded to 3 fluorine atoms and has 2 lone pairs.
- **Lone pairs**: 2

- **ICl₄⁻**:
- Central atom: Iodine (I)
- Structure: I is bonded to 4 chlorine atoms and has 2 lone pairs.
- **Lone pairs**: 2

- **XeOF₄**:
- Central atom: Xenon (Xe)
- Structure: Xe is bonded to 4 fluorine atoms and 1 oxygen (double bond), resulting in 1 lone pair.
- **Lone pairs**: 1

- **ClOF₃**:
- Central atom: Chlorine (Cl)
- Structure: Cl is bonded to 3 fluorine atoms and 1 oxygen (double bond), resulting in 1 lone pair.
- **Lone pairs**: 1

- **SCl₂**:
- Central atom: Sulfur (S)
- Structure: S is bonded to 2 chlorine atoms and has 2 lone pairs.
- **Lone pairs**: 2

- **OSF₄**:
- Central atom: Sulfur (S)
- Structure: S is bonded to 4 fluorine atoms and 1 oxygen (double bond), resulting in 0 lone pairs.
- **Lone pairs**: 0

3. **Count the species with 2 lone pairs**:
- The species with 2 lone pairs are:
- XeF₄
- XeF₅⁻
- XeF₃⁺
- ICl₄⁻
- SCl₂

Total = 5 species

### Final Answer:
The total number of species in which the central atoms have two lone pairs of electrons is **5**.

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