Arenes (aromatic hydrocarbons) are characterized by their unusual stability, which is attributed to the complete delocalisation of their $\pi$ electrons and resonance . Because addition reactions would destroy this highly stable aromatic $\pi$ system, arenes resist addition reactions under normal conditions . Instead, their characteristic reactions are electrophilic substitution reactions, which preserve the aromatic ring . Therefore, electrophilic addition is not a characteristic property of arenes.