Briefly describe how the reactivity of benzene and substituted benzene can be established ? ?

The reactivity of benzene and substituted benzene can be established through various experimental techniques such as measuring reaction rates, studying the products formed, and analyzing the stability of intermediates. Additionally, computational methods can be used to predict reactivity based on electronic structure and molecular orbitals. Reactivity can also be inferred from the presence of activating or deactivating groups on the benzene ring, as well as the presence of ortho, meta, or para directing groups that influence the regioselectivity of reactions. Overall, a combination of experimental and theoretical approaches can be used to establish the reactivity of benzene and its derivatives.