Chemistry - Complete Pblock- Question with Solution | TestHub

${\mathrm{BF}}_3$ forms complex halides of the type $\left[{\mathrm{BF}}_4^{-}\right]$in which B atom has C.N. 4 , it cannot extend its C.N. beyond 4 due to the nonavailability of $d$-orbitals in its configuration. Hence, ${\mathrm{BF}}_6^{3-}$ ion $(s{p}^3{d}^2$ hybridisation) is not formed. On the other hand, $\mathrm{Al}$ can extend its C.N. beyond 4 due to the availability of $d$-orbitals in its configuration.