Which of the following functional groups primarily exerts a powerful (electron withdrawing) resonanc — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

A group exerts a $-M$ effect if the atom attached to the conjugated system is bonded to a more electronegative atom via a multiple bond. The nitro group ($-NO_2$) strongly pulls $\pi$ -electron density out of the ring, leaving partial positive charges at the ortho and para positions.