Among the following species, the smallest ion is : 

1.	Na+	2.	F-
3.	O2-	4.	N3-

 The correct order for electron affinity of halogens is :

1. Br > F

2. F > Cl

3. Br > Cl

4. F > I

Element/Ion that has the highest electron affinity is : 

Allred Rochow's scale is related to:
 

1. Electronegativity, radius, and Z^*

2. Resonance energy of the molecule, ionisation potential and electron affinity.

3. Bond Polarity, diagonal relationship and periodicity.

4. None of the above.

Increasing order of ionic radii and decreasing order of number of protons of the given isoelectronic species is:-

1. Ca⁺², K⁺, Cl^-, S^-2

2. Cl^-, Ca⁺², K⁺, S^-2

3. S^-2, Cl^-, Ca⁺², K⁺

4. None of the above

The electronic configuration of Palladium is:

1. [Rn] 5f³ 6d¹ 7s²

2. [Rn] 5f⁵ 6d¹ 7s²

3. [Rn] 5f² 6d¹ 7s²

4. None of the above.

The element having very high electron affinity but zero ionisation enthalpy is :-

1. He (due to inert gas configuration)

2. Be (due to fully filled subshell)

3. H (due to presence of allotropes)

4. None of the above

The electronic configuration of chalcogens in their outermost shell is : 

1. ${\mathrm{ns}}^2{\mathrm{np}}^3$ $$ $$ $$    

2. ${\mathrm{ns}}^2{\mathrm{np}}^4$ $$ $$ $$     

3. ${\mathrm{ns}}^2{\mathrm{np}}^5$           

4. ${\mathrm{ns}}^2{\mathrm{np}}^6$

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 -