# Is translational/rotational KE conserved when diatomic molecules collide?

When two diatomic molecules of a gas collide, is the collision elastic or inelastic? Is rotational KE also conserved/not conserved?

My guess is that translational KE is conserved while rotational KE isn't. I'm just guessing for the translational part, but as for the rotational part I can imagine two molecules "canceling each other out" if one spins clockwise / the other counterclockwise and they bump into each other.