From kinetic theory, what is the approximate order of the dimension of an atom?

What is the kinetic theory of gases? How is it useful?

What are the characteristics of the molecular model of an ideal gas according to the kinetic theory of gases?

The average distance between molecules of an ideal gas at $STP$ is approximately of the order of

State whether the following statements are True or False:
$(i)$ Attractive or repulsive forces act between molecules of an ideal gas.
$(ii)$ The potential energy of an ideal gas is zero.
$(iii)$ Molecules of all gases are the same in size.
$(iv)$ Molecules of an ideal gas are perfectly elastic spheres.

What is an ideal gas?