Magnetic moment of Xⁿ⁺ (Z = 26) is $\sqrt{24}$ B.M. Hence, number of unpaired electrons and value of n respectively are :

Magnetic movement = n

$$\begin{gathered} \sqrt{\mathrm{n}(\mathrm{n}+2)} \\ \sqrt{4(4+2)} \\ \sqrt{24} \end{gathered}$$

Here ,n = number of unpaired electron=4

Z=26⟶Fe Since it has 4 unpaired electron ,it will be Fe ²⁴ Whose electronic configeration is(Ar)3d⁶

Hence in Xⁿ⁺⟶X=Fe n=2