Question

what is the hybridization of the central atom in the iodine trifluoride (if₃) molecule?

Explanation:

Step1: Determine valence - electron number of central atom

Iodine (I) in group 7A has 7 valence electrons.

Step2: Determine number of bonding pairs and lone pairs

In $IF_3$, iodine forms 3 bonds with fluorine atoms. The number of bonding pairs ($BP$) is 3. Using the formula for the number of lone - pairs ($LP$): $LP=\frac{V - BP}{2}$, where $V = 7$ (valence electrons of I) and $BP = 3$. So $LP=\frac{7 - 3}{2}=2$.

Step3: Calculate the steric number

The steric number ($SN$) is the sum of bonding pairs and lone pairs. $SN=BP + LP=3 + 2=5$.

Step4: Determine hybridization

A steric number of 5 corresponds to $sp^{3}d$ hybridization.

Answer:

$sp^{3}d$