The molecule `ML_(x)` is planar with 7 pairs of electrons around M in the valence shell. The value of x is :

Options

A. 6
B. 5
C. 4
D. 3

Answer

To solve the question regarding the molecule \( ML_x \) which is planar with 7 pairs of electrons around the central atom \( M \) in the valence shell, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Total Number of Electron Pairs**:
- We are given that there are 7 pairs of electrons around the central atom \( M \). This means the total number of electron pairs is 7.

2. **Determine the Steric Number**:
- The steric number is defined as the sum of the number of bond pairs and lone pairs of electrons around the central atom.
- Therefore, we can write:
\[ \text{Steric Number} = \text{Number of Bond Pairs} + \text{Number of Lone Pairs} = 7 \]

3. **Identify the Hybridization**:
- The steric number of 7 indicates that the hybridization of the central atom \( M \) is \( sp^3d^3 \). This hybridization corresponds to a specific geometry.

4. **Analyze the Geometry**:
- The hybridization \( sp^3d^3 \) typically leads to a pentagonal bipyramidal geometry. However, since the molecule is specified to be planar, we focus on the pentagonal planar arrangement.
- In a pentagonal planar arrangement, there are 5 bonding pairs and 2 lone pairs.

5. **Determine the Value of \( x \)**:
- Since the molecule is of the form \( ML_x \) and we have established that there are 5 bond pairs (from the 5 atoms \( L \)) and 2 lone pairs, we can conclude that:
\[ x = 5 \]

6. **Final Answer**:
- Therefore, the value of \( x \) is \( 5 \).

### Summary:
The value of \( x \) in the molecule \( ML_x \) is \( 5 \), making the compound \( ML_5 \).

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