In terms of increasing non-metallic character, which of the following is the
correct order for the elements N, P, O, and S?

1. P < S < N < O

2. O < S < N < P 

3. O < N < S < P 

4. N < S < O < P

The correct order of metallic character of elements B, Al, Mg and K  is :

What is the correct order of non-metallic character for the elements B, C, N, F, and Si?

The correct order of their chemical reactivity of the elements F, Cl, O and N in terms of oxidizing property is :

Which of the following oxide is amphoteric in nature?

1. SnO

2. ${\mathrm{SiO}}_2$

3. ${\mathrm{GeO}}_2$

4. ${\mathrm{CO}}_2$

The element with the electronic configuration \(1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^3 4 s^2\)belongs to:

1. V group

2. XV group

3. II group

4. III group

Ionic radii are :

(1) Inversely proportional to effective nuclear charge.

(2) Inversely proportional to square of effective nuclear charge.

(3) Directly proportional to effective nuclear charge.

(4) Directly proportional to square of effective nuclear charge.

The atomic species that has the maximum ionization energy is : 

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⁺ 

Incorrect statement among the following is-

1) Elements are classified into periods and groups

2) Elements with similar properties are placed in the same group

3) This makes the study of elements simpler

4) Elements are placed according to decreasing atomic number