boron trifluoride - a pungent colorless gas

halide - a salt of any halogen acid

hydrogen fluoride - a colorless poisonous corrosive liquid made by the action of sulphuric acid on calcium fluoride; solutions in water are hydrofluoric acid

stannous fluoride - a white powder that is used to fluoridate toothpaste

sulfur hexafluoride, sulphur hexafluoride - a colorless gas that is soluble in alcohol and ether; a powerful greehouse gas widely used in the electrical utility industry