One element has atomic weight 39. Its electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹. The true statement for this element is: 

1. High value of IE                               

2. Transition element

3. Isotone with \(^{38}_{18} A r\)   $$

4. None of the above

Identify the INCORRECT match.

The first ionisation potential of Na, Mg and Si are 496, 737 and 786 kJ mol${}^{-1}$ 
respectively. The ionisation potential of Al will be closer to

1. 760 kJ mol${}^{-1}$ 

2. 575 kJ mol${}^{-1}$ 

3. 801 kJ mol${}^{-1}$ 

4. 419 kJ mol${}^{-1}$ 

Which one of the following is true about metallic character when we move from left
to right in a period and top to bottom in a group?

1. Decreases in a period and increases down the group

2. Increases in a period and decreases in a group

3. Increases both in the period and the group

4. Decreases both in the period and in the group

How does electron affinity change when we move from left to right in a period in the
periodic table?

1. Generally increases

2. Generally decreases

3. Remains unchanged

4. First increases and then decreases

One mole of magnesium in the vapour state absorbed 1200 kJ mol^-1 of energy.

If the first and second ionization energies of Mg are 750 and 1450 kJ mol^-1 respectively,

the final composition of the mixture is

1. 86% Mg⁺ + 14% Mg²⁺ 

2. 36% Mg⁺ + 64% Mg²⁺ 

3. 69% Mg⁺ + 31% Mg²⁺ 

4. 31% Mg⁺ + 69% Mg²⁺ 

Which group best illustrates the transition from non-metallic behavior with increasing atomic number?

1.  Be, Mg, Ca, Sr

2.  N, P, As, Sb

3.  F, Cl, Br, l

4.  Fe, Ru, Os, Hs

Which of the following isoelectronic species has the largest radius?

1.  $K^{+}$

2.  $C{a^2}^{+}$

3.  $P^{3-}$

4.  $S^{2-}$

What property of the oxygen atom is represented by the equation : $O\left(g\right)+e^{-}\to O^{-}\left(g\right)$?

1.  Electronegativity

2.  First electron affinity

3.  First ionization energy

4.  Lattice energy

In which list are atoms of the elements Be, B, Mg and Al arranged from smallest to largest atomic radius?

1.  Be < B < Mg < Al

2.  Mg < Be < Al < B

3.  B < Be < Al < Mg

4.  Al < Mg < B < Be