The correct order of the decreasing ionic radii among the following isoelectronic species is : 

1. Ca²⁺ > K⁺ > S^2- > Cl^-

2. Cl^- > S^2- > Ca²⁺ > K⁺

3. S^2- > Cl^- > K⁺ > Ca²⁺

4. K⁺ > Ca²⁺ > Cl^- > S^2-

The correct order of increasing electron gain enthalpy with a negative sign for the elements O, S, F, and Cl is : 

1. Cl < F < S < O                   

2. O < S < F < Cl

3. F < S < O < Cl                   

4. S < O < Cl < F

Which one of the following compounds is a peroxide ?

1. KO₂

2. BaO₂

3. MnO₂

4. NO₂

The sequence of ionic mobility in aqueous solution is

1. K⁺>Na⁺>Rb⁺>Cs⁺

2. Cs⁺>Rb⁺>K⁺>Na⁺

3. Rb⁺>K⁺>Cs⁺>Na⁺

4. Na⁺>K⁺>Rb⁺>Cs⁺

Which one of the following arrangements does not give the correct picture of the trends indicated against it?

(1) F₂ > Cl₂ > Br₂ > I₂ :Oxidising power

(2) F₂ < Cl₂ > Br₂ > I₂ : Electron gain enthalpy

(3) F₂ > Cl₂ > Br₂ > I₂ : Bond dissociation energy

(4) F₂ > Cl₂ > Br₂ > I₂: Electronegativity

Identify the correct order of the size of the following:

(1) Ca²⁺<K⁺<Ar<S^2-<Cl^-

(2) Ca²⁺<K⁺<Ar<Cl^-<S^2-

(3) Ar<Ca²⁺<K⁺<Cl^-<S^2-

(4) Ca²⁺<Ar<K⁺<Cl^-<S^2-

An element whose IUPAC name is Ununtrium (Uut) belongs to:

1. s-Block elements                       

2. p-Block elements

3. d-Block elements                              

4. Inner transition elements .

Which among the following is not a representative element?

The period number and group number of "Tantalum" (Z=73) are respectively :

Consider the following electronic configuration of an element (P) :

$\left[\mathrm{Xe}\right]4{\mathrm{f}}^{14}5{\mathrm{d}}^{1}6{\mathrm{s}}^2$

The correct statement about element 'P' is :

1. It belongs to the 6th period and the 1st group.

2. It belongs to the 6th period and the 2nd group.

3. It belongs to the 6th period and the 3rd group.

4. None of the above.