Nitrogen was isolated by the British physician Daniel Rutherford in 1772 and recognized as an elemental gas by the French chemist Antoine Laurent Lavoisier about 1776. Properties Nitrogen is a colorless, odorless, tasteless, nontoxic gas. It can be condensed into a colorless liquid, which can in turn be compressed into a colorless, crystalline solid. Nitrogen exists in two natural forms of isotopes, and four radioactive isotopes have been artificially prepared. Nitrogen melts at -210.01?é?? C -346.02?é?? F, boils at -195.79?é?? C -320.42?é?? F, and has a density of 1.251 g/liter at 0?é?? C 32?é?? F. The atomic weight of nitrogen...
ammonia produced in this manner, a wide variety of important chemical products are prepared, including fertilizers, nitric acid, urea, hydrazine, and amines. In addition, an ammonia compound is used in the preparation of nitrous oxide N2O a colorless gas popularly known as laughing gas. Mixed with oxygen, nitrous oxide is used as an anesthetic for some types of surgery. Used as a coolant, liquid nitrogen has found widespread application in the field of cryogenics. With the recent advent of ceramic materials that become superconductive at the boiling point of nitrogen, the use of nitrogen as a coolant is increasing.