Spray cans produce an aerosol ,which is ____.

উত্তরঃ Spray cans produce an aerosol, the technical term for a very fine spray. They do this by means of a pressurized propellant, which is a liquid that boils at everyday temperatures. Inside the can, a layer of gaseous pressure increased, and eventually, it becomes so high that boiling stops. When the nozzle is pressed, the gas pressure forces the product up the tube in the can and out of the nozzle in a spray or foam. The propellant may emerge as well but, now under less pressure, it immediately evaporates. First patented in the US in 1941, aerosol spray cans have been used as convenient packages for an ever - increasing range of products including paints, insecticides, and shaving cream to name a few. The can is filled with the product to be sprayed and the propellant, a compressed gas such as butane or Freon. The gas is partly liquefied by the pressure in the can, but there is a layer of free gas above the liquid. As the can empties liquefied gas vaporizes to fill the space.