Question: what are the physical and chemical properties of ammonia?
Answer: Ammonia is a colourless gas with a characteristically pungent smell. It is lighter than air, its density being 0.589 times that of air. It is easily liquefied due to the strong hydrogen bonding between molecules; the liquid boils at −33.3 °C (−27.94 °F), and freezes to white crystals at −77.7 °C (−107.86 °F).