Question

Highest magnetic moment is shown by the ion
(A) ${V^{ + 3}}$
(B) $C{o^{ + 3}}$
(C) $F{e^{ + 3}}$
(D) $C{r^{ + 3}}$

Answer 1

Hint : Magnetic moment is also called magnetic dipole moment. It is the measure of an object's tendency to align with the magnetic field. Magnetic Moment can be defined as the magnetic strength and orientation of a magnet or other object that produces a magnetic field.
$\sqrt {n(n + 2)}$

Complete Step By Step Answer:
Magnetic moment is generated by two methods: The motion of electric charge and spin angular momentum. Magnetic moment is measured by an instrument called a magnetometer. Not all the magnetometers are aligned to calculate the magnetic moment directly. Some of these measure only magnetic fields. From the measured magnetic field, the magnetic moments are measured. In a diamagnetic material, the electron orbits are random and all the magnetic moments are cancelled. All the spins are almost paired. So, the net magnetic moment in a diamagnetic material is zero. The formula of magnetic moment for spin is given by $\sqrt {n(n + 2)}$ .
${V^{ + 3}} \to 3{d^2}$
$C{o^{ + 3}} \to 3{d^6}$
$F{e^{ + 3}} \to 3{d^5}$
$C{r^{ + 3}} \to 3{d^4}$
Remember that the magnetic moment is directly proportional to the number of unpaired electrons. ${V^{ + 3}}$ has only two unpaired electrons. $C{o^{ + 3}}$ and $C{r^{ + 3}}$ has four unpaired electrons. $F{e^{ + 3}}$ has five unpaired electrons.
Therefore, option C is the correct answer.

Note :
Magnetic Dipole has two unlike poles which have equivalent strength and are separated by a small distance. Magnetic Dipole Moment can be described as the product of pole strength and the distance between the two poles. The distance between the two poles of a given magnetic dipole is called the magnet length.