All the following molecules are polar except one

Options

A. `BCl_(3)`
B. `CH_(2)Cl_(2)`
C. `NH_(3)`
D. `FNO`

Explanation

To determine which of the given molecules is non-polar, we will analyze the molecular geometry and the electronegativity of the atoms involved in each molecule.

### Step-by-Step Solution:

1. **Identify the Molecules**: The question states that we need to identify which of the following molecules is non-polar. The molecules mentioned are BCl3, CH2Cl2, NH3, and FNO.

2. **Analyze BCl3**:
- **Structure**: BCl3 (Boron Trichloride) has a trigonal planar structure due to sp2 hybridization.
- **Bond Angles**: The bond angles are 120 degrees.
- **Polarity**: The molecule has three B-Cl bonds, which are polar due to the difference in electronegativity between boron and chlorine. However, because of its symmetrical shape, the dipole moments cancel each other out, making BCl3 a non-polar molecule.

3. **Analyze CH2Cl2**:
- **Structure**: CH2Cl2 (Dichloromethane) has a tetrahedral structure due to sp3 hybridization.
- **Polarity**: The presence of two different types of atoms (Cl and H) attached to the central carbon atom creates a net dipole moment. Therefore, CH2Cl2 is a polar molecule.

4. **Analyze NH3**:
- **Structure**: NH3 (Ammonia) has a pyramidal structure due to the presence of a lone pair on nitrogen.
- **Polarity**: The N-H bonds are polar, and the lone pair creates an asymmetry in the molecule, resulting in a net dipole moment. Thus, NH3 is a polar molecule.

5. **Analyze FNO**:
- **Structure**: FNO (Fluoro-nitroso) has a bent structure due to the presence of different atoms.
- **Polarity**: The difference in electronegativity between F, N, and O leads to polar bonds, and the bent shape results in a net dipole moment. Therefore, FNO is also a polar molecule.

6. **Conclusion**: After analyzing all the molecules, we find that BCl3 is the only non-polar molecule among the options provided.

### Final Answer:
The non-polar molecule among the given options is **BCl3**.