How will you justify that the collision among the gas molecules are perfectly elastic?

Explanation

According to the kinetic theory, the collisions of the gas molecules among themsleves and also with the walls of the container are perfectly elastic. This means that the collisions are fricationless and there is no loss of kinetic energy in the collisions. Had it not been so, some energy might have been lost during each collisions and the molecule must ultimately come to rest. But this does not happen. This clearly shows tht the collisions are of elastic nature. Howevert the molecules may exchnage energy during the collisions.