Question

Which one of the following ions has the highest magnetic moment?

• A. $M{n}^{2+}$
• B. $Z{n}^{2+}$
• C. $C{a}^{2+}$
• D. $K^{+}$

Answer 1

Answer: (A)

$M{n}^{2+}$ has 5 unpaired electrons in the 3d-sub-shell; whereas $Z{n}^{2+},C{a}^{2+}$ and $K^{+}$ ions have all the electrons paired and, therefore, are diamagnetic. Magnetic moment depends upon the number of unpaired electrons. The more the number of unpaired electrons in an atom or ion, the greater is its magnetic moment. Thus, $M{n}^{2+}$ has the highest magnetic moment.