p-Block Elements: Diagram-Based Questions (5)

Cl has 7 valence $e^-$. Three are bonded to F, leaving 2 lone pairs. Total electron pairs: $3 + 2 = 5 \to sp^3 d$.

Shape: T-shaped (trigonal bipyramidal with two equatorial lone pairs). Bond angles slightly less than $90°$ (around $87°$) because lone pairs squeeze bonds.

Br has 7 valence $e^-$. Five bonded to F, one lone pair remains. Total pairs: $5 + 1 = 6 \to sp^3 d^2$.

Shape: square pyramidal (octahedral with one position occupied by lone pair). Bond angles close to but less than $90°$.

I has 7 valence $e^-$. Seven bonded to F, no lone pairs. Total pairs: $7 \to sp^3 d^3$.

Shape: pentagonal bipyramidal. Bond angles: equatorial $72°$, axial-equatorial $90°$.

As we move down Group 17 (Cl $\to$ Br $\to$ I), atomic size and number of available $d$ orbitals increase. Larger atoms accommodate more bonded atoms around them, expanding the octet further. This is why $\text{IF}_7$ exists while $\text{ClF}_7$ does not.