Final answer:
The Fe atom in the complex [Fe(H₂O)₄(Br)₂]⁺ exhibits d²sp³ hybridization according to valence bond theory.
Step-by-step explanation:
The complex ion [Fe(H₂O)₄(Br)₂]⁺ contains a Fe atom in its central position. According to valence bond theory, the Fe atom in this complex exhibits d²sp³ hybridization. This means that the Fe atom has one s orbital, three p orbitals, and two d orbitals that participate in bonding.