Polarity and Reactivity H 6+ -CI chloromethane chloromethane Halogens are more electronegative than C. Carbon-halogen bond is polar,so carbon has partial positive charge. Carbon can be attacked by a nucleophile. Halogen can leave with the electron pair. Chapter6 3Chapter 6 3 Polarity and Reactivity • Halogens are more electronegative than C. • Carbon—halogen bond is polar, so carbon has partial positive charge. • Carbon can be attacked by a nucleophile. • Halogen can leave with the electron pair