What I'm asking is a quite simple physics question. I know what I'm asking - what I don't know is why you don't at least try to give a definite answer. I'm tryi

What I'm asking is a quite simple physics question. I know what I'm asking - what I don't know is why you don't at least try to give a definite answer. I'm trying to make it clearer (let me know if it's not clear enough): I have a container with two compartments, separated by a moving wall. In each side there is an equal volume of gas at normal temperature and pressure (helium and neon). What happens when the moving wall is removed? A) The gases will mix. B) The gases will not mix. C) I have no way of knowing. It depends on the positions and velocities of each of the particles and they will either mix or they won't. The usual (wrong?) answer is A. But it seems that you could (should?) answer C. Because you cannot rule out the possibility that they don't mix - you would be guessing.