Discuss the nature of the $C-X$ bond in halogen compounds.

(N/A) In halogen compounds, the carbon-halogen bond is polar: Halogen atoms are located on the right side of the periodic table. The electronegativity of all halogen atoms $(F, Cl, Br, I)$ is higher than that of the carbon atom. Due to this, the electrons of the carbon-halogen $(C-X)$ bond are shifted towards the halogen, causing the carbon to acquire a partial positive charge and the halogen to acquire a partial negative charge, making the $C-X$ bond polar.
$(b)$ Trends in polarity, bond length, and bond enthalpy from $C-F$ to $C-I$: As we move down the group in the periodic table, the size of the halogen atoms $(F, Cl, Br, I)$ increases. Fluorine is the smallest and iodine is the largest.
Therefore, the carbon-halogen bond length increases from $C-F$ to $C-I$. The bond length, bond enthalpy, and dipole moment of $C-X$ bonds in methyl halides $(CH_3X)$ are given in the table below:

Bond	Bond Length $(pm)$	$C-X$ Bond Enthalpy $(kJ \ mol^{-1})$	Dipole Moment $(Debye)$
$CH_3-F$	$139$	$452$	$1.847$
$CH_3-Cl$	$178$	$351$	$1.860$
$CH_3-Br$	$193$	$293$	$1.830$
$CH_3-I$	$214$	$234$	$1.636$

Order of bond length: $CH_3-F$ < $CH_3-Cl$ < $CH_3-Br$ < $CH_3-I$
Order of dipole moment: $CH_3-Cl$ > $CH_3-F$ > $CH_3-Br$ > $CH_3-I$