The anionic part of solid ${\text{Cl}}_2{\text{O}}_{6_{ }}$ is having the state hybridization of central atom is

Hybridization of Central Atom in Anionic Part of Solid Cl₂O₆

Upon dissociation in the solid state, Cl₂O₆ forms two ionic species:

• ClO₂⁺ (cationic part)
• ClO₄^- (anionic part)

The hybridization of the central atom (chlorine) in the anionic part, which is ClO₄^-, is sp³.

This is because the chlorine atom in ClO₄^- has four regions of electron density (bonded to four oxygen atoms), which corresponds to sp³ hybridization.