Chemistry - Complete Pblock- Question with Solution | TestHub

Boron is an element of 13 group and contains three electrons in its valence shell. When its compound ${\mathrm{BH}}_3$ dimerises, each boron atom carry only $6e^{-}$, that is their octet is incomplete. Hence, ${\left({\mathrm{BH}}_3\right)}_2$ is an electron deficient compound. In all other given molecules octet of central atom is complete.