Identify the incorrect statement among the following:

• There is a decrease in the radii of the atoms or ions as one proceeds from La to Lu.

• Lanthanoid contraction is the accumulation of successive shrinkages

• As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements

• As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements

Which one of the following ions is the most stable in aqueous solution?

• Cr³⁺

• V³⁺

• Ti³⁺

• Ti³⁺

More the number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is:

• more energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals

• the lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals

• the greater metallic character of the lanthanoids than that of the corresponding actinoids

• the greater metallic character of the lanthanoids than that of the corresponding actinoids

It is because of inability of ns² electrons of the valence shell to participate in bonding that

• Sn²⁺ is reducing while Pb⁴⁺ is oxidising

• Sn²⁺ is oxidising while Pb⁴⁺ is reducing

• Sn²⁺ and Pb²⁺ are both oxidising and reducing

• Sn²⁺ and Pb²⁺ are both oxidising and reducing

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

• The radioactive nature of actinoids

• Actinoid contraction

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

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

Name the gas that can readily decolourises acidified KMnO₄ solution

• CO₂

• SO₂

• NO₂

• NO₂

The correct increasing order of ionic radii of the following Ce³⁺, La³⁺, Pm³⁺ and Yb³⁺ is 

• Yb³⁺ < Pm³⁺< Ce³⁺<La³⁺

• Ce³⁺< Yb³⁺<Pm³⁺<La³⁺

• Yb³⁺< Pm³⁺< La³⁺<Ce³⁺

• Pm³⁺ < La³⁺< Ce³⁺ < Yb³⁺

The shape of gaseous SnCl₂ is

• Tetrahedral

• Linear

• Angular

• T-shape

[CuCl₄]^2- exists while [CuI₄]^2- does not exist, because

• I^- is stronger reductant than Cl^-

• I^- is weaker reductant than Cl^-

• I^- is stronger oxidant than Cl^-

• None of the above

Actinides exhibit larger number of oxidation state than that of corresponding lanthanides. The reason behind this aspect is

• lesser energy difference between 5f and 6d-orbitals than between 4f and 5d-orbitals

• larger atomic size of actinides than the lanthanides

• more energy difference between 5f and 6d orbitals than between 4f and 5d-orbitals

• greater reactive nature of the actinides than the lanthanides