According to kinetic molecular theory of gases, which of the following statements are correct?

(A) The actual volume of the molecules is negligible in comparison to the empty space between them.

(B) Collisions of gas molecules are inelastic.

(C) At any particular time, different particles in the gas have same speed and same kinetic energies.

(D) Pressure is exerted by the gas as a result of collision of the particles with the walls of the container.

What is the ratio of kinetic energy of 7 grams of nitrogen and 4 grams of oxygen at $T(\mathrm{~K})$ ?

Equal amount of gases are kept in two separate containers. If densities of the two gases are in $1: 2$ ratio and their temperatures are in 2:1 ratio, calculate the ratio of their respective pressures.

The volume of a given amount of gas at $27^{\circ} \mathrm{C}$ at constant pressure is $420 \mathrm{~cm}^3$. If the temperature is reduced by $20^{\circ} \mathrm{C}$ at constant pressure, what will be the volume of the gas?