Alkyl halides are a group of chemical compounds derived from alkanes containing one or more halogens. Halogen atoms are more electronegative than carbon atoms, and so the C-Hal bond is polarized in such a way that there is partial positive charge on the carbon and partial negative charge on the halogen. Typically the chemistry of alkyl halides is dominated by this effect, and usually results in the C-X bond breakageeither in a substitution or elimination process .This reactivity makes alkyl halides useful chemical reagents.