The correct order of bond strength for the given species is:

Match the following molecules in Column $I$ with the number of lone pairs on their central atom in Column $II$.

Column $I$ (Molecules)	Column $II$ (Number of lone pairs on central atom)
$A. \ NH_3$	$1. \ \text{Two}$
$B. \ H_2O$	$2. \ \text{Three}$
$C. \ XeF_2$	$3. \ \text{Zero}$
$D. \ CH_4$	$4. \ \text{Four}$
	$5. \ \text{One}$

What is the formal charge on the $N$ atom in the $NH_4^{+}$ ion?

Draw Lewis structures of the following molecules and ions: $H_2S$,$SiCl_4$,$BeF_2$,$CO_3^{2-}$,$HCOOH$.

The formal charge on the central oxygen atom in ozone $(O_3)$ is:

Among the following,the correct statement$(s)$ is(are):
$A$. $Al(CH_3)_3$ has the three-centre two-electron $(3c-2e)$ bonds in its dimeric structure.
$B$. $BH_3$ has the three-centre two-electron $(3c-2e)$ bonds in its dimeric structure $(B_2H_6)$.
$C$. $AlCl_3$ has the three-centre two-electron bonds in its dimeric structure.
$D$. The Lewis acidity of $BCl_3$ is greater than that of $AlCl_3$.