Ammonia (chemical formula: NH3) is a compound of nitrogen and hydrogen. As a colorless pungent gas, it is highly soluble in water to become the liquid ammonia. It is also one of the most abundant nitrogen-containing compound in the atmosphere. It provides the fundamental nutrients demands for various kinds of organisms by serving as a precursor of their food and fertilizer. It is also important for various kinds of biological processes. In addition, it serves as a building blocks of many kinds of commercially important nitrogen compounds as well as pharmaceutical products. The major application of ammonia is acting as the fertilizer to supply the nitrogen source of plants and animals. It is used in the manufacture of commercial explosive such as TNT. It is applied to textile industry for the manufacture of nylon and rayon, the dyeing and scouring of cotton and silk as well as being used as a catalyst in the production of some synthetic resins. It also has applications in various metallurgical processes and fermentation processes. It can even be used as a cleaner and antimicrobial reagent in the food. Finally, it is also an important routine reagent used in lab. For example, liquid ammonia is a common solvent in the lab. In current days, ammonia is produced by the Haber-Bosch process which has industrial hydrogen be reacted with atmospheric nitrogen under high temperature and pressure in the presence of catalyst. For small-scale lab synthesis, ammonia can also be manufactured through the heating of urea and Ca (OH)2. Low concentration of ammonia has no significant effect on human beings. However, exposure to high concentration of gaseous ammonia can result in lung damage and even death, thus protective measures should be taken during the operation.