Answer:

GASSES

AnswerCrossword Clue
GASSESReleases vapor
GASSESHelium and neon
GASSESGreat times, slangily
GASSESFuels (up)
GASSESFills (up), as a car
GASSESTalks boastfully: Slang.
GASSESTalks idly or boastfully: Slang.
GASSESSupplies with fuel.
GASSESChats idly: Slang.
GASSESChitchats
GASSESShoots the breeze
GASSESHelium and neon, e.g.
GASSESDangerous buildup in a mine
GASSESFills the tank, with "up"
GASSESNeon and argon
GASSESNeon and argon, for two (Var.)
GASSESHydrogen and methane (Var.)
GASSESHydrogen and methane
GASSESRadon and carbon dioxide, e.g. (Var.)
GASSESHelium and neon, for two
GASSESSome are combustible
GASSESNeon and others