Which of the following molcules have three lone pairs around central atom -

Options

A. `I_(3)^(-)`
B. `XeF_(2)`
C. `ICl_(2)^(-)`
D. `CIF_(3)`

Explanation

To determine which of the given molecules have three lone pairs around the central atom, we will analyze each option step by step.

### Step 1: Analyze Option A - I3^-
1. Identify the central atom: Iodine (I).
2. Count the valence electrons: Iodine has 7 valence electrons.
3. Count the surrounding atoms: There are 2 iodine atoms surrounding the central iodine.
4. Calculate the steric number:
\[ \text{Steric Number} = \text{Valence Electrons} + \frac{\text{Number of Surrounding Atoms}}{2} + \text{Charge} \]
\[ = 7 + \frac{2}{2} + 1 = 7 + 1 = 8 \]
5. Determine the geometry: The steric number of 5 corresponds to a trigonal bipyramidal (TBP) geometry.
6. Count the lone pairs: In I3^-, there are 3 lone pairs around the central iodine atom.

### Step 2: Analyze Option B - XeF2
1. Identify the central atom: Xenon (Xe).
2. Count the valence electrons: Xenon has 8 valence electrons.
3. Count the surrounding atoms: There are 2 fluorine atoms surrounding the central xenon.
4. Calculate the steric number:
\[ \text{Steric Number} = 8 + \frac{2}{2} = 8 + 1 = 5 \]
5. Determine the geometry: The steric number of 5 corresponds to a trigonal bipyramidal (TBP) geometry.
6. Count the lone pairs: In XeF2, there are 3 lone pairs around the central xenon atom.

### Step 3: Analyze Option C - ICl2^-
1. Identify the central atom: Iodine (I).
2. Count the valence electrons: Iodine has 7 valence electrons.
3. Count the surrounding atoms: There are 2 chlorine atoms surrounding the central iodine.
4. Calculate the steric number:
\[ \text{Steric Number} = 7 + \frac{2}{2} + 1 = 7 + 1 = 8 \]
5. Determine the geometry: The steric number of 5 corresponds to a trigonal bipyramidal (TBP) geometry.
6. Count the lone pairs: In ICl2^-, there are also 3 lone pairs around the central iodine atom.

### Step 4: Analyze Option D - ClF3
1. Identify the central atom: Chlorine (Cl).
2. Count the valence electrons: Chlorine has 7 valence electrons.
3. Count the surrounding atoms: There are 3 fluorine atoms surrounding the central chlorine.
4. Calculate the steric number:
\[ \text{Steric Number} = 7 + \frac{3}{2} = 7 + 1.5 = 5 \]
5. Determine the geometry: The steric number of 5 corresponds to a trigonal bipyramidal (TBP) geometry.
6. Count the lone pairs: In ClF3, there are only 2 lone pairs around the central chlorine atom.

### Conclusion:
The molecules that have three lone pairs around the central atom are:
- **Option A: I3^-**
- **Option B: XeF2**
- **Option C: ICl2^-**