Which best describes the molecules of an ideal gas

Options are as follow,

A)  Constant volume, no intermolecular forces of attraction,energy loss in collisions 

B)  No volume, strong intermolecular forces of attraction, perfectly elastic collisions

C)  Constant volume, no intermolecular forces of attraction, energy gain during collisions

D)  No volume, no intermolecular forces of attraction, perfectly elastic collisions

            Option-D (No volume, no intermolecular forces of attraction, perfectly elastic collisions) is the correct answer.

Explanation:
                   As we know there are no interactions between gas molecules due to which they lack shape and volume and occupies the shape and volume of container in which they are kept. So, we can skip Option-B. 
                   Secondly we also know that the gas molecules move randomly. They collide with the walls of container causing pressure and collide with each other. And these collisions are perfectly elastic and no energy is lost or gained during collisions. Therefore Option-A and C are skipped.
                   Now we are left with only Option-D, In option D it is given that ideal gas has no volume. This is true related to Ideal gas as it is stated in ideal gas theories that molecules are far apart from each other and the actual volume of gas molecules compared to volume of container is negligible. Hence, for ideal gas Option-D is a correct answer.

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