Phosphorous can form `PCl_(5)` molecule in the excited state of phosphorous atom. But the formation of `PH_(5)` is not possible in the same state. How do you account for this?

Explanation

To understand why phosphorus can form \( PCl_5 \) but cannot form \( PH_5 \), we need to analyze the bonding characteristics and orbital interactions involved in both cases.

### Step-by-Step Solution:

1. **Electron Configuration of Phosphorus**:
- Phosphorus (P) has the atomic number 15. Its electron configuration is \( 1s^2 2s^2 2p^6 3s^2 3p^3 \).
- In the ground state, phosphorus has 5 valence electrons (2 in the 3s orbital and 3 in the 3p orbitals).

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