The C–X bond is polarized because halogen (X) is more electronegative than carbon (C). Due to this high electronegativity of halogen, it gains a negative charge by attracting the electron cloud towards itself. Carbon, on the other hand, gets a positive charge because of its low electronegativity. Halogens only need one electron to reach their noble gas configuration, which is why a sigma bond is created between a halogen and a carbon atom. The length of the C–X bond in haloarenes increases after an increase in the atomic size from fluorine and astatine. Due to this, there is a decrease in the C–X bond dissociation strength.