Vsepr Theory And Shape Of Molecules

To determine the number of lone pairs on the central atom in each molecule, we use the Valence Shell Electron Pair Repulsion (VSEPR) Theory. Step 1: Lone Pairs in
- Chlorine (Cl) has 7 valence electrons.
- Fluorine atoms use 3 bonding pairs, leaving 2 lone pairs.
- Molecular geometry: T-shaped.
Thus, the lone pairs on = 2.
Step 2: Lone Pairs in
- Nitrogen (N) has 5 valence electrons.
- Three fluorine atoms form 3 bonding pairs, leaving 1 lone pair.
- Molecular geometry: Trigonal pyramidal.
Thus, the lone pairs on = 1.

Step 3: Lone Pairs in
- Sulfur (S) has 6 valence electrons.
- Four fluorine atoms form 4 bonding pairs, leaving 1 lone pair.
- Molecular geometry: Seesaw.
Thus, the lone pairs on = 1.
Step 4: Lone Pairs in
- Xenon (Xe) has 8 valence electrons.
- Four fluorine atoms form 4 bonding pairs, leaving 2 lone pairs.
- Molecular geometry: Square planar.
Thus, the lone pairs on = 2.
Step 5: Verify the Correct Answer
From our calculations, the number of lone pairs on the central atoms is , which matches Option (3).