Valence shell electron pair repusin theory `(VSEPR)` can be used
to perdict the approximate shape of molecules. Electrons in
bonds and in lone pairs can ve thought of as `"charge cloud"` that
repel one another and stay as far apart possible, thus causing molecules to assume specific shapes.
The repulsive interacions of electro paris decrease in the order :
Lone pair-lone pair `gt` Lone pair -bond pair `gt`Bond pair -bond
pair.
These replusions effect result in deviations from
idealized shapes and alternative in bond angles in molecules.
The species which has pyramidal shape is :

Options

A. `ICl_(3)`
B. `SO_(3)`
C. `PCl_(3)`
D. `overset(ddot)(N)H_(3)`

Answer

To determine the species that has a pyramidal shape using the Valence Shell Electron Pair Repulsion (VSEPR) theory, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the VSEPR Theory**:
The VSEPR theory states that electron pairs (both bonding pairs and lone pairs) around a central atom will arrange themselves to minimize repulsion. This arrangement leads to specific molecular geometries.

2. **Identify the Electron Pair Geometry**:
- For a pyramidal shape, we typically look for a central atom that is surrounded by three bonding pairs and one lone pair of electrons. This corresponds to an sp³ hybridization.

3. **Use the Hybridization Formula**:
The hybridization can be determined using the formula:
\[ X = \frac{1}{2} \left( \text{Valence Electrons on Central Atom} + \text{Monovalent Atoms} - \text{Charge on Cation} + \text{Charge on Anion} \right) \]
Here, we need to find species that fit this criteria.

4. **Examine Given Species**:
- **ICl₃**:
- Valence electrons on I = 7
- Monovalent atoms (Cl) = 3
- Total = 7 + 3 = 10; \(X = \frac{10}{2} = 5\) → sp³d (trigonal bipyramidal, not pyramidal)
- **SO₃**:
- Valence electrons on S = 6
- Monovalent atoms (O) = 3
- Total = 6 + 0 = 6; \(X = \frac{6}{2} = 3\) → sp² (trigonal planar, not pyramidal)
- **PCl₃**:
- Valence electrons on P = 5
- Monovalent atoms (Cl) = 3
- Total = 5 + 3 = 8; \(X = \frac{8}{2} = 4\) → sp³ (pyramidal due to one lone pair)
- **NH₃**:
- Valence electrons on N = 5
- Monovalent atoms (H) = 3
- Total = 5 + 3 = 8; \(X = \frac{8}{2} = 4\) → sp³ (pyramidal due to one lone pair)

5. **Conclusion**:
The species that has a pyramidal shape are **PCl₃** and **NH₃**.

### Final Answer:
The species which has a pyramidal shape is **PCl₃** and **NH₃**.