Which molecule has trigonal planar geometry ?

Options

A. `BF_(3)`
B. `NH_(3)`
C. `PCl_(3)`
D. `IF_(3).`

Explanation

To determine which molecule has a trigonal planar geometry, we can analyze the molecular structures of the given examples. Let's go through the analysis step by step:

### Step 1: Identify the Molecules
The molecules we need to consider are:
1. BF3 (Boron trifluoride)
2. NH3 (Ammonia)
3. PCl3 (Phosphorus trichloride)
4. IF3 (Iodine trifluoride)

### Step 2: Determine the Valence Electrons
- **BF3**: Boron (B) has 3 valence electrons, and each Fluorine (F) has 7 valence electrons. In BF3, Boron forms three bonds with Fluorine.
- **NH3**: Nitrogen (N) has 5 valence electrons. In NH3, Nitrogen forms three bonds with Hydrogen (H) and has one lone pair.
- **PCl3**: Phosphorus (P) has 5 valence electrons. In PCl3, Phosphorus forms three bonds with Chlorine (Cl) and has one lone pair.
- **IF3**: Iodine (I) has 7 valence electrons. In IF3, Iodine forms three bonds with Fluorine and has two lone pairs.

### Step 3: Analyze the Molecular Geometry
- **BF3**: With three bond pairs and no lone pairs, BF3 adopts a trigonal planar geometry.
- **NH3**: With three bond pairs and one lone pair, NH3 has a pyramidal geometry.
- **PCl3**: Similar to NH3, PCl3 has three bond pairs and one lone pair, resulting in a pyramidal geometry.
- **IF3**: With three bond pairs and two lone pairs, IF3 has a T-shaped geometry.

### Step 4: Conclusion
From the analysis, the only molecule that exhibits a trigonal planar geometry is **BF3**.

### Final Answer
The molecule with trigonal planar geometry is **BF3**.

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