The increasing order of non-metallic character of the elements N, P, O, and S is: 

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 :

Considering the elements B, C, N, F, and Si; the correct order of their non-metallic character is :

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

1. F > Cl > O > N

2. F > O > Cl > N

3. Cl > F > O > N

4. O > F > N > Cl

Which of the following oxide is amphoteric in nature?

1. SnO

2. ${\mathrm{SiO}}_2$

3. ${\mathrm{GeO}}_2$

4. ${\mathrm{CO}}_2$

An atom has electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³ 4s² , you will place it in :

(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