To account for the hexavalency in SF6 one electron each from 3s and 3p orbitals is promoted to 3d orbitals as shown in fig.1.27(b). These six orbitals get hybridised to form six sp3d2hybrid orbitals. Each of these sp3d2 hybrid orbitals overlaps with 2p orbital of fluorine to form S-F bond.
The answer is S(sp3d2)- F(p)
