Which of the following oxide is amphoteric in nature?

1. SnO

2. ${\mathrm{SiO}}_2$

3. ${\mathrm{GeO}}_2$

4. ${\mathrm{CO}}_2$

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 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⁺ 

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 :

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