Question

How does the kinetic-molecular theory explain why 1 mol of krypton and 1 mol of helium have the same volume at STP?

Answer 1

The gas molecule consist of a large number of individual particles.

The volume of each particle is negligible as compared to the volume of the container.

The individual gas particles are in constant, random, straight-line motion.

The collision of the particles are elastic.

The collide particles exchange their energy but they do not any energy during friction. Therefore, the kinetic energy of the particle is constant

All these reason make their volumes similar since they follow the kinetic molecular theory