A singular atom traversing the vacuum of space, belting out Bobby Vinton? No. Liquids, gases, and solids are functions of temperature and pressure, which are defined by proximity to other atoms.

If you have one molecule of every (non-reactive) gas possible sharing space in a teeny tiny pressure vessel, it could still be deemed a gas mixture if it doesn't sublimate or condense. We just don't have the kinematic equations to describe how that mixture works in a specific sense, just that it still acts like a gas in a general sense.

CO2 is still a gas entrained in soda, even if the H2O molecules separate each CO2 molecule out by a thousand miles. We say this because if we agitate all million square miles, the CO2 comes out and floats off with the rest of the gases.