The bond angles in molecules `H_(2)O, NH_(3), CH_(4) and CO_(2)` are in the order :

Options

A. `H_(2)O gt NH_(3) gt CH_(4) gt CO_(2)`
B. `H_(2)O lt NH_(3) lt CO_(2) lt CH_(4)`
C. `H_(2)Olt NH_(3) lt CH_(4) lt CO_(2)`
D. `H_(2)O gt NH_(3) lt CH_(4) gt CO_(2)`.

Explanation

To determine the bond angles in the molecules H₂O, NH₃, CH₄, and CO₂, we will analyze each molecule step by step, focusing on their hybridization and molecular geometry.

### Step 1: Determine the Hybridization and Geometry of Each Molecule

1. **H₂O (Water)**
- **Valence Electrons**: Oxygen (O) has 6 valence electrons, and there are 2 hydrogen (H) atoms contributing 1 electron each.
- **Total**: 6 + 2 = 8 valence electrons.
- **Hybridization**: (6 + 2) / 2 = 4 → SP³ hybridization.
- **Geometry**: Bent shape due to 2 lone pairs.
- **Bond Angle**: Approximately 104.5°.

2. **NH₃ (Ammonia)**
- **Valence Electrons**: Nitrogen (N) has 5 valence electrons, and there are 3 hydrogen atoms contributing 1 electron each.
- **Total**: 5 + 3 = 8 valence electrons.
- **Hybridization**: (5 + 3) / 2 = 4 → SP³ hybridization.
- **Geometry**: Trigonal pyramidal due to 1 lone pair.
- **Bond Angle**: Approximately 107°.

3. **CH₄ (Methane)**
- **Valence Electrons**: Carbon (C) has 4 valence electrons, and there are 4 hydrogen atoms contributing 1 electron each.
- **Total**: 4 + 4 = 8 valence electrons.
- **Hybridization**: (4 + 4) / 2 = 4 → SP³ hybridization.
- **Geometry**: Tetrahedral with no lone pairs.
- **Bond Angle**: 109.5°.

4. **CO₂ (Carbon Dioxide)**
- **Valence Electrons**: Carbon (C) has 4 valence electrons, and there are 2 oxygen atoms contributing 6 electrons each.
- **Total**: 4 + 12 = 16 valence electrons.
- **Hybridization**: (4 + 0) / 2 = 2 → SP hybridization.
- **Geometry**: Linear with no lone pairs.
- **Bond Angle**: 180°.

### Step 2: Order the Bond Angles

Now that we have determined the bond angles for each molecule, we can arrange them in order from smallest to largest:

- H₂O: 104.5°
- NH₃: 107°
- CH₄: 109.5°
- CO₂: 180°

### Final Order of Bond Angles

The bond angles in the molecules H₂O, NH₃, CH₄, and CO₂ are in the order:

**H₂O < NH₃ < CH₄ < CO₂**