Which of the following 3d transition metal cations possesses the maximum possible spin-only magnetic — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Magnetic moment depends on the number of unpaired electrons ($n$). $Mn^{2+}$ is $3d^5$ ($n=5$). $Fe^{2+}$ is $3d^6$ ($n=4$). $Cr^{3+}$ is $3d^3$ ($n=3$). $Ni^{2+}$ is $3d^8$ ($n=2$). $Mn^{2+}$ yields the maximum moment of $\sqrt{35} \approx 5.92 \text{ B.M.}$