Assign the correct bond angles to each of the following molecules.
Molecules : `H_(2)O,BeF_(2),CH_(4),NH_(3),BCl_(3),SF_(6).`
Bond angles : `90^(@),107^(@),109^(@),104.5^(@),120^(@),180^(@)`

Answer

To assign the correct bond angles to the given molecules, we will analyze each molecule based on its structure and the arrangement of electron pairs around the central atom. Here’s a step-by-step solution:

### Step 1: Analyze H₂O (Water)
- **Structure**: Water has a bent shape due to the presence of two lone pairs on the oxygen atom.
- **Bond Angle**: The bond angle is approximately **104.5°**.

### Step 2: Analyze BeF₂ (Beryllium Fluoride)
- **Structure**: Beryllium has two valence electrons and forms two bonds with fluorine atoms, resulting in a linear structure.
- **Bond Angle**: The bond angle is **180°**.

### Step 3: Analyze CH₄ (Methane)
- **Structure**: Methane has four bond pairs around the carbon atom, leading to a tetrahedral geometry.
- **Bond Angle**: The bond angle is **109.5°**, but it is often rounded to **109°**.

### Step 4: Analyze NH₃ (Ammonia)
- **Structure**: Ammonia has three bond pairs and one lone pair on the nitrogen atom, resulting in a trigonal pyramidal shape.
- **Bond Angle**: The bond angle is approximately **107°**.

### Step 5: Analyze BCl₃ (Boron Trichloride)
- **Structure**: Boron has three valence electrons and forms three bonds with chlorine atoms, resulting in a trigonal planar structure.
- **Bond Angle**: The bond angle is **120°**.

### Step 6: Analyze SF₆ (Sulfur Hexafluoride)
- **Structure**: Sulfur has six bond pairs and forms an octahedral geometry.
- **Bond Angle**: The bond angle is **90°**.

### Summary of Bond Angles:
- H₂O: **104.5°**
- BeF₂: **180°**
- CH₄: **109°**
- NH₃: **107°**
- BCl₃: **120°**
- SF₆: **90°**

### Final Answer:
- H₂O → 104.5°
- BeF₂ → 180°
- CH₄ → 109°
- NH₃ → 107°
- BCl₃ → 120°
- SF₆ → 90°