The species in which the central atom uses sp2? hybrid orbitals in its bonding is

Options

A. `SO_2`
B. `PH_3`
C. `NH_3`
D. `SbH_3`

Answer

To determine which species has a central atom that uses sp² hybrid orbitals in its bonding, we can follow these steps:

### Step 1: Identify the Compounds
We have four compounds to analyze:
1. Sulfur dioxide (SO₂)
2. Phosphine (PH₃)
3. Ammonia (NH₃)
4. Antimony trisulfide (SbS₃)

### Step 2: Determine the Valence Electrons of the Central Atom
- **Sulfur in SO₂**: Sulfur has 6 valence electrons.
- **Phosphorus in PH₃**: Phosphorus has 5 valence electrons.
- **Nitrogen in NH₃**: Nitrogen has 5 valence electrons.
- **Antimony in SbS₃**: Antimony has 5 valence electrons.

### Step 3: Analyze Each Compound for Hybridization
1. **Sulfur Dioxide (SO₂)**:
- Sulfur forms two sigma bonds (one with each oxygen) and has one lone pair.
- Hybridization index = Number of sigma bonds + Number of lone pairs = 2 + 1 = 3.
- This corresponds to sp² hybridization.

2. **Phosphine (PH₃)**:
- Phosphorus forms three sigma bonds (one with each hydrogen) and has one lone pair.
- Hybridization index = 3 + 1 = 4.
- This corresponds to sp³ hybridization.

3. **Ammonia (NH₃)**:
- Nitrogen forms three sigma bonds (one with each hydrogen) and has one lone pair.
- Hybridization index = 3 + 1 = 4.
- This corresponds to sp³ hybridization.

4. **Antimony Trisulfide (SbS₃)**:
- Antimony forms three sigma bonds (one with each sulfur) and has one lone pair.
- Hybridization index = 3 + 1 = 4.
- This corresponds to sp³ hybridization.

### Step 4: Conclusion
From the analysis, only sulfur dioxide (SO₂) has a central atom (sulfur) that uses sp² hybrid orbitals in its bonding. Therefore, the correct answer is:

**Answer: Sulfur dioxide (SO₂)**

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