The incorrect match among the following is:

1. B < C < N < O (increasing first ionisation enthalpy)

2. I < Br < F < Cl (increasing electron gain enthalpy)

3. Li < Na < K < Rb (increasing metallic radius)

4. Al³⁺ < Mg²⁺ < Na⁺ <F^- (increasing ionic size)

The correct sequence of increasing radii is - 

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

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 .

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.

Which of the following statements is correct regarding the element Unununium?

1. It is an inner transition element.

2. It belongs to the 8th period in the periodic table.

3. It is a transition element.

4. It is a non-transition element.

Consider the following periodic properties:

(i) Atomic radius
(ii) Electronegativity
(iii) Ionisation energy
(iv) Metallic character
Which of these properties decrease from left to right across a period and increase from top to bottom down a group?

The radius of which ion is closest to that of $L{i}^{+}$ ion ?

1. $N{a}^{+}$                                       

2. $B{e}^{2+}$

3. $M{g}^{2+}$                                       

4. $A{l}^{3+}$