This video demonstrates a simple chemical reaction between ammonia (NH3) and hydrochloric acid (HCl) to form the salt ammonium chloride (NH4Cl). When the reaction takes place between the two reactants as their vapors mix in the air the solid ammonium chloride product is formed in flowing trails ideal for beautiful smoke photography. To receive a free audio book and support my channel, visit my sponsor Audible through this link: http://www.audible.com/nhil By the way, thank you all for 500,000 subscribers! It's been an awesome experience to interact with you and read your comments for all these years! I still read every single comment on all of my videos and I respond to as many as I possibly can! #NightHawkInLight ~-~~-~~~-~~-~ Check out my latest video: "How To View Invisible Air Currents With Lasers" https://www.youtube.com/watch?v=K94Cc21KEIA ~-~~-~~~-~~-~