What is an ideal gas?

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 are macroscopic quantities and microscopic quantities?

Molecules of a gas behave like

Write the importance of the kinetic theory of gases.

Can we consider a container of irregular shape while calculating the pressure of an ideal gas? Why?