Which of the following groups will exert the strongest positive mesomeric () effect when attached di — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

The magnitude of the $+M$ effect depends on the availability of the lone pair for donation into the $\pi$ system. Nitrogen is less electronegative than oxygen and chlorine, meaning it holds onto its lone pair less tightly. Therefore, the $-NH_2$ group can donate its electrons more readily, exerting the strongest $+M$ effect among the given options.