1. Identify the geometry corresponding to square pyramidal

A square pyramidal molecular shape arises when the central atom has:

• $6$ electron pairs around it,
• with arrangement $AX_5E$.

So total electron-pair geometry is octahedral, and one lone pair gives square pyramidal shape.

2. Check each given species

We examine the interhalogens one by one.

(i) $\mathrm{ClF_3}$

Central atom $= \mathrm{Cl}$

• Valence electrons on Cl $= 7$
• Forms $3$ bonds with F
• Lone pairs on Cl $= 2$

Thus it is $AX_3E_2$. Molecular shape: T-shaped, not square pyramidal.

(ii) $\mathrm{IF_7}$

Central atom $= \mathrm{I}$

• $7$ bonds, $0$ lone pairs
• Type $AX_7$

Molecular shape: pentagonal bipyramidal, not square pyramidal.

(iii) $\mathrm{BrF_5}$

Central atom $= \mathrm{Br}$

• $5$ bonds, $1$ lone pair
• Type $AX_5E$

Molecular shape: square pyramidal.

(iv) $\mathrm{BrF_3}$

Central atom $= \mathrm{Br}$

• $3$ bonds, $2$ lone pairs
• Type $AX_3E_2$

Molecular shape: T-shaped, not square pyramidal.

(v) $\mathrm{I_2Cl_6}$

This is dimeric, analogous to $\mathrm{Al_2Cl_6}$-type bridged structure, and is not a simple interhalogen with one central atom showing $AX_5E$. It does not have square pyramidal molecular geometry.

(vi) $\mathrm{IF_5}$

Central atom $= \mathrm{I}$

• $5$ bonds, $1$ lone pair
• Type $AX_5E$

Molecular shape: square pyramidal.

(vii) $\mathrm{ClF}$

Diatomic molecule.

Shape is simply linear, not square pyramidal.

(viii) $\mathrm{ClF_5}$

Central atom $= \mathrm{Cl}$

• $5$ bonds, $1$ lone pair
• Type $AX_5E$

Molecular shape: square pyramidal.

3. Count square pyramidal species

The species having square pyramidal structure are:

• $\mathrm{BrF_5}$
• $\mathrm{IF_5}$
• $\mathrm{ClF_5}$

So, total number is $3$

4. Comparison with stored answer

Stored correct answer $= 3$. Our derived answer $= 3$. They match.