Question

How many lone pairs are present in $I_3^{-}$ at central atom?

Answer 1

$I_3^{-}$ is in $ds{p}^3$ hybridized state.

It contains $3$ lone pairs and $2$ bond pairs of valence electrons around the central iodine because iodine having access to $4d$ sublevel orbitals since having electrons in the fourth energy level.