The pair of elements where the addition of a second electron to each atom is endothermic is:

1. N, Ne

2. Be, F

3. B, C

4. All of the above

The correct order in which the O-O bond

length increases in the following is

1. H₂O₂<O₂<O₃

2. O₃<H₂O₂<O₂

3. O₂<O₃<H₂O₂

4. O₂<H₂O₂<O₃

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

If atomic number of an element of He-family is Z then which of the following atomic number will highest EA?

(1) Z - 2

(2) Z - 1

(3) Z + 1

(4) Z + 2

The jump between the \(5^{th}\) and \(6^{th}\) ionization energies is large, suggesting the element has how many protons in its nucleus?

The first four IP values of an element are 19, 190, 2000 and 2600 eV/atom. Element belongs to:-

(1) Amphoteric elements

(2) Four electron donor group

(3) s-block

(4) All of the above

Atomic radius of Be, O, C, N, B are respectively (in pm) :-

(1) 111, 66, 77, 74, 88

(2) 74, 84, 111, 77,66

(3) 111, 88, 77, 74, 66

(4) 111, 66, 88, 77,74

Removal of 2^nd electron is always:

1. Endothermic

2. Endothermic for Mg, Be, N

3. Exothermic for Mg, Be, N, and noble gases

4. Depends of electronic configuration

Z_eff of Na⁺ and Na⁰ are respectively:

1. 1.95 and 1.22

2. 0.85 and 0.35

3. 1 and 0.35

4. 6.85 and 2.2

The electronic configuration of Palladium is:

1. [Kr] 5f³ 6d¹ 7s²

2. [Kr] 5f⁵ 6d¹ 7s²

3. [Kr] 5f² 6d¹ 7s²

4. None of the above.