Which pair has elements containing a same number of electrons in the outermost orbit?

1. N, O

2. Na, Ca

3. As, Bi

4. Pb, Sb

The correct arrangement of increasing order of atomic radius among Na, K, Mg and Rb is 

1. Mg<K<Na<Rb

2. Mg<Na<K<Rb

3. Mg<Na<Rb<K

4. Na<K<Rb<Mg

Which of the following statement is correct with respect to the property of elements with increase in atomic number in carbon family.

1. Their metallic character decreases

2. The stability of +2 oxidation state increases

3. Their ionisation energy increases

4. Their atomic size decreases

The correct order of second ionization potential of carbon, nitrogen, oxygen and fluorine is

1. C > N > O > F

2. O > N > F > C

3. O > F > N > C

4. F > O > N > C

The electronic configuration of the element which is just above the element with atomic 43 in the same group is ____________.

1. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²

2. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s³ 4p⁶

3. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²

4. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷ 4s²

Generally, the ionization enthalpy increases along a period but there are some exceptions. The one which is not an exception is-

1. Be and B

2. N and O

3. Mg and Al

4. Na and Mg

Sodium generally does not show an oxidation state of +2, because of:

1. High first ionization potential.

2. High second ionization potential.

3. Large ionic radius.

4. High electronegativity.

The electronegativity of the following elements increases in the order of:

The graph of the first ionization enthalpy versus atomic number as follows:

Which of the following statement is correct?

1. Alkali metals are at the maxima and noble gases at the minima.

2. Noble gases are at the maxima and alkali metals at the minima.

3. Transition element are at the maxima.

4. Minima and Maxima do not show any regular behaviour.

What is the combining ratio of a number of elements in group l with elements in group 17th of the periodic table ?

1. 1 : 2

2. 1 : 3

3. 2 : 1

4. 1 : 1