Which of the following have $3c-2e^-$ bonds?
$I. \ Al_2Cl_6, \ II. \ B_2H_6, \ III. \ Fe_2Cl_6, \ IV. \ Si_2H_6$

Which of the following molecules follows the octet rule?

The bond dissociation energy of $B-F$ in $BF_3$ is $646 \ kJ \ mol^{-1}$ whereas that of $C-F$ in $CF_4$ is $515 \ kJ \ mol^{-1}.$ The correct reason for higher $B-F$ bond dissociation energy as compared to that of $C-F$ is

Bond dissociation energies of $HF, HCl, HBr$ follow the order:

Which of the following molecules is electron-deficient?

Arrange the following bonds in increasing order of bond length and provide the reason: $C-C$,$C=C$,$C\equiv C$.