Covalent compounds are soluble in ..............

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

The potential energy curve for the $H_2$ molecule as a function of internuclear distance is:

For the formation of a covalent bond,the difference in the value of electronegativities should be

Which of the following has the strongest bond?

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