In which of the following , central atom does not have one lone pairs of electron ?

Options

A. `PCl_(5)`
B. `NH_(3)`
C. `PCl_(3)`
D. `XeF_(6)`

Answer

To determine which of the given compounds has a central atom that does not have a lone pair of electrons, we will analyze each option step by step.

### Step 1: Analyze PCl5
- **Central Atom**: Phosphorus (P)
- **Valence Electrons**: Phosphorus has 5 valence electrons.
- **Bonds Formed**: PCl5 has 5 chlorine (Cl) atoms bonded to phosphorus.
- **Bond Pairs**: 5 (one for each Cl)
- **Lone Pairs**: 0 (since all valence electrons are used in bonding)
- **Conclusion**: PCl5 has no lone pairs on the central atom.

### Step 2: Analyze NH3
- **Central Atom**: Nitrogen (N)
- **Valence Electrons**: Nitrogen has 5 valence electrons.
- **Bonds Formed**: NH3 has 3 hydrogen (H) atoms bonded to nitrogen.
- **Bond Pairs**: 3 (one for each H)
- **Lone Pairs**: 2 valence electrons remain, which form 1 lone pair.
- **Conclusion**: NH3 has one lone pair on the central atom.

### Step 3: Analyze PCl3
- **Central Atom**: Phosphorus (P)
- **Valence Electrons**: Phosphorus has 5 valence electrons.
- **Bonds Formed**: PCl3 has 3 chlorine (Cl) atoms bonded to phosphorus.
- **Bond Pairs**: 3 (one for each Cl)
- **Lone Pairs**: 2 valence electrons remain, which form 1 lone pair.
- **Conclusion**: PCl3 has one lone pair on the central atom.

### Step 4: Analyze XeF6
- **Central Atom**: Xenon (Xe)
- **Valence Electrons**: Xenon has 8 valence electrons (as a noble gas).
- **Bonds Formed**: XeF6 has 6 fluorine (F) atoms bonded to xenon.
- **Bond Pairs**: 6 (one for each F)
- **Lone Pairs**: 2 valence electrons remain, which form 1 lone pair.
- **Conclusion**: XeF6 has one lone pair on the central atom.

### Final Conclusion
After analyzing all the options:
- **PCl5**: 0 lone pairs
- **NH3**: 1 lone pair
- **PCl3**: 1 lone pair
- **XeF6**: 1 lone pair

The compound in which the central atom does not have any lone pairs of electrons is **PCl5**.

### Answer
The correct option is **PCl5**.