The pair of species with similar shape is

Options

A. `PCl_(3), NH_(3)`
B. `CF_(4),SF_(4)`
C. `PbCl_(2),CO_(2)`
D. `PF_(5),IF_(5)`

Answer

To determine which pair of species has a similar shape, we will analyze the molecular geometry and hybridization of each species mentioned in the question.

### Step-by-Step Solution:

1. **Identify the species**: The species we need to analyze are PCl3, NH3, CF4, SF4, PbCl2, CO2, PF5, and IF5.

2. **Analyze PCl3**:
- Phosphorus (P) has 5 valence electrons.
- It forms 3 bond pairs with 3 chlorine (Cl) atoms and has 1 lone pair.
- Hybridization: \( sp^3 \) (3 bond pairs + 1 lone pair).
- Shape: Trigonal pyramidal.

3. **Analyze NH3**:
- Nitrogen (N) has 5 valence electrons.
- It forms 3 bond pairs with 3 hydrogen (H) atoms and has 1 lone pair.
- Hybridization: \( sp^3 \) (3 bond pairs + 1 lone pair).
- Shape: Trigonal pyramidal.

4. **Compare PCl3 and NH3**:
- Both have the same hybridization \( sp^3 \) and the same shape (trigonal pyramidal).

5. **Analyze CF4**:
- Carbon (C) has 4 valence electrons.
- It forms 4 bond pairs with 4 fluorine (F) atoms.
- Hybridization: \( sp^3 \) (4 bond pairs).
- Shape: Tetrahedral.

6. **Analyze SF4**:
- Sulfur (S) has 6 valence electrons.
- It forms 4 bond pairs with 4 fluorine atoms and has 1 lone pair.
- Hybridization: \( sp^3d \) (4 bond pairs + 1 lone pair).
- Shape: Seesaw.

7. **Analyze PbCl2**:
- Lead (Pb) has 4 valence electrons.
- It forms 2 bond pairs with 2 chlorine atoms and has 1 lone pair.
- Hybridization: \( sp^2 \) (2 bond pairs + 1 lone pair).
- Shape: Bent.

8. **Analyze CO2**:
- Carbon (C) has 4 valence electrons.
- It forms 2 bond pairs with 2 oxygen (O) atoms.
- Hybridization: \( sp \) (2 bond pairs).
- Shape: Linear.

9. **Analyze PF5**:
- Phosphorus (P) has 5 valence electrons.
- It forms 5 bond pairs with 5 fluorine atoms.
- Hybridization: \( sp^3d \) (5 bond pairs).
- Shape: Trigonal bipyramidal.

10. **Analyze IF5**:
- Iodine (I) has 7 valence electrons.
- It forms 5 bond pairs with 5 fluorine atoms and has 1 lone pair.
- Hybridization: \( sp^3d^2 \) (5 bond pairs + 1 lone pair).
- Shape: Square pyramidal.

### Conclusion:
The pair of species with similar shape is **PCl3 and NH3**, both having a trigonal pyramidal shape.