Identify the incorrect statements related to lanthanons:
 

1.	Europium shows +2 oxidation state.
2.	The basicity decreases as the ionic radius decreases from Pr to Lu.
3.	All the lanthanons are much more reactive than aluminium.
4.	Ce+4 solutions are widely used as oxidizing agents in volumetric analysis.

The reason for a greater range of oxidation states in actinoids is attributed to:

1. Actinoid contraction

2. 5f, 6d and 7s levels having comparable energies.

3. 4f and 5d levels being close in energies.

4. The radioactive nature of actinoids

Match  Column I with Column II and mark the most appropriate option:

When copper is heated with conc. HNO₃ it produces:

1. Cu(NO₃) and NO

2. Cu(NO₃)₂, NO and NO₂

3. Cu(NO₃)₂ and N₂O

4. Cu(NO₃)₂ and NO₂

SO₂ is passed through an acidified K₂Cr₂O₇ solution.
The correct statement among the following regarding the above experiment is:

1. The solution gets decolorized.

2. SO₂ gets reduced.

3. Green coloured Cr₂(SO₄)₃ gets formed.

4. The solution turns blue.

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

1. $\left[Xe\right]4 f^8 6d^2$

2. $\left[Xe\right]4 f^9 5s^1$

3. $\left[Xe\right]4 f^7 5d^{1}6s^2$

4. $\left[Xe\right]4 f^6 5d^{2}6s^2$

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).