Nucleophilic Substitution H:X: Nuc The nucleophile Nuc:displaces the leaving group X from the carbon atom by using its lone pair to form a new bond to the carbon atom. Elimination A new nt bond is formed by the elimination of halide ion and another atom(usually H) -C-+B:→ B-H +C=C H:X: In a dehydrohalogenation,the base(B:)abstracts a proton from the alkyl halide Most nucleophiles can also act as bases,therefore the preference for elimination or substitution depends on the reaction conditions and the alkyl halide used. Ch06 Alkyl Halides (landscape) Page 8 Ch06 Alkyl Halides (landscape) Page 8 Nucleophilic Substitution The nucleophile Nuc:- displaces the leaving group X￾from the carbon atom by using its lone pair to form a new bond to the carbon atom. Elimination A new  bond is formed by the elimination of halide ion and another atom (usually H+ ). In a dehydrohalogenation, the base (B:- ) abstracts a proton from the alkyl halide. Most nucleophiles can also act as bases, therefore the preference for elimination or substitution depends on the reaction conditions and the alkyl halide used