The diagram that shows molecules in both the liquid phase and the gas phase is the one where:

  • There is a cluster of particles close together at the bottom (these are the liquid molecules, closely spaced but not in a rigid pattern).
  • There are also individual particles spread far apart in the space above the liquid (these are gas molecules).

So, if the answer choices are pictures:

  • Not all tightly packed in a fixed pattern (that would be only solid).
  • Not all spread far apart everywhere (that would be only gas).
  • Not all close together but filling the entire container (that would be only liquid).
  • The correct one must clearly show:
    • A “pool” of particles at the bottom.
    • Some particles floating well above, widely spaced.

Choose the option that matches that description (often labeled something like “B” or “4” in typical worksheets), but without seeing your specific diagrams, that’s the general rule to pick the right one.