Nitrogen

A colorless nonmetallic element of atomic number 7 tasteless and odorless comprising four fifths of the atmosphere by volume in the form of molecular nitrogen N2 It is chemically very inert in the free state and as such is incapable of supporting life hence the name azote still used by French chemists but it forms many important compounds such as ammonia nitric acid the cyanides etc and is a constituent of all organized living tissues animal or vegetable Symbol N Atomic weight 14007 It was formerly regarded as a permanent noncondensible gas but was liquefied in 1877 by Cailletet of Paris and Pictet of Geneva and boils at 1958 deg C at atmospheric pressure Liquid nitrogen is used as a refrigerant to store delicate materials such as bacteria cells and other biological materials