Calculate the value of X-Y, for `XeOF_(4)`. (X=Number of `sigma` bond pair and Y=Number of lone pair on central atom )

Explanation

To calculate the value of \( X - Y \) for \( XeOF_4 \), where \( X \) is the number of sigma bond pairs and \( Y \) is the number of lone pairs on the central atom (xenon), we can follow these steps:

### Step 1: Determine the Valence Electrons
Xenon (Xe) is a noble gas in group 18 and has 8 valence electrons. Oxygen (O) has 6 valence electrons, and each fluorine (F) has 7 valence electrons. Since there are 4 fluorine atoms, we calculate the total valence electrons as follows:
- Valence electrons from Xe = 8
- Valence electrons from O = 6
- Valence electrons from 4 F = \( 4 \times 7 = 28 \)

Total valence electrons = \( 8 + 6 + 28 = 42 \)

### Step 2: Draw the Lewis Structure
In the Lewis structure of \( XeOF_4 \):
- Xenon is the central atom.
- It forms bonds with 4 fluorine atoms and 1 oxygen atom.
- Each bond (Xe-F and Xe-O) is a sigma bond.

### Step 3: Count the Sigma Bonds
In \( XeOF_4 \):
- There are 4 Xe-F sigma bonds.
- There is 1 Xe-O sigma bond.

Total sigma bonds \( X = 4 + 1 = 5 \).

### Step 4: Determine the Lone Pairs
After forming 5 sigma bonds, we need to determine how many lone pairs are left on the xenon atom. Xenon starts with 8 valence electrons, and it uses 6 electrons (2 for each bond) for bonding:
- Used for bonding = \( 5 \text{ bonds} \times 2 = 10 \) electrons.

Since xenon can expand its octet, it can accommodate more than 8 electrons. However, in this case, it has 1 lone pair remaining after forming the bonds:
- Total lone pairs \( Y = 1 \).

### Step 5: Calculate \( X - Y \)
Now we can find \( X - Y \):
\[ X - Y = 5 - 1 = 4 \]

### Final Answer
The value of \( X - Y \) for \( XeOF_4 \) is \( 4 \).

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