Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?

1.	\(\text{ [Xe] } 4f^8 6 d^2\)	2.	\(\text { [Xe]}4 f^9 5 s^1\)
3.	\(\text { [Xe] } 4f^7 5 d^1 6 s^2\)	4.	\(\text { [Xe]} 4f^6 5 d^2 6 s^2\)

Assuming complete ionization, same moles of which of the following compounds will require the least amount of acidified KMnO₄ for complex oxidation?

1. $FeS{O}_4$

2. $FeS{O}_3$

3. $Fe{C}_2{O}_4$

4. $Fe{\left(N{O}_2\right)}_2$

A pair among the following have nearly the same atomic radii:
(Numbers in the parenthesis are atomic numbers).

Which of the following processes does not involve the oxidation of iron?

The number of d -electrons in Fe²⁺ (atomic number  Z = 26)  is different from the number of:
1. s-electrons in Mg (Z = 12)
2. p-electrons in Cl (Z = 17)
3. d-electrons in Fe (Z = 26)
4. p-electrons in Ne (Z = 10)

The pair of compounds that can exist together is:

1. FeCl₃, SnCl₂

2. HgCl₂, SnCl₂

3. FeCl₂, SnCl₂

4. FeCl₃, Kl

The reason for the lanthanoid contraction is:

1. negligible screening effect of 'f' orbitals.

2. increasing nuclear charge.

3. decreasing nuclear charge.

4. decreasing screening effect.

Which of the following statements is false?