The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of the transition element, which shows the highest magnetic moment.

1.	$3d^7$	2.	$3d^5$
3.	$3d^8$	4.	$3d^2$

Which of the following oxidation state is common for all lanthanoids?

Gadolinium (atomic number 64) is an element of the 4f series, Identify the correct electronic configuration of gadolinium from the following options:

\(1. (X e) 4 f^{7} 5 d^{1} 6 s^{2} \)

2. \( (X e) 4 f^{6} 5 d^{2} 6 s^{2}\)

3. \((X e) 4 f^{8} 6 d^{2}\)

4. \((X e) 4 f^{9} 5 s^{1}\)

Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds? 

The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Determine the spin only magnetic moment value of $C{r}^{3+}$ ion:

Why is the highest oxidation state of manganese in fluorides +4 (as in MnF₄​), while the highest oxidation state in oxides is +7 (as in Mn₂O₇​)?

Although zirconium belongs to 4d transition series and hafnium to 5d transition series even then they show similar physical and chemical properties because:

In the titration of KMnO₄ or its use as an oxidizing agent, the medium is acidified with dilute H₂SO₄ rather than HCl because:

A pair of ions that have the same electronic configuration among their constituent species is:

1. \(Sr^{3+}, Cr^{3+}\)
2. \(Fe^{3+}, Mn^{2+}\)
3. \(Fe^{3+}, Co^{3+}\)
4. \(Cr^{3+}, Fe^{3+}\)

Electronic configuration of a transition element X in +3 oxidation state is [Ar]$3d^5$. What is its atomic number?