The `S_(N^(2)` reactivity order for halides is :

Reactivity order for S_(N)1

Reactivity order for S_(N)1

(A) S_(N^(2)) reaction takes place in single step. (R) S_(N^(2)) reaction involves the reactivity order of alkyl halides as 1^(@) gt 2^(@) gt 3^(@) halides.

(A): S_(N^(2)) reaction takes place in single step. (R): S_(N^(2)) reaction involves the reactivity order of alkyl halides as 1^@ gt 2^@ gt 3^@ halides.