The atomic mass of nitrogen is 14.00674 atomic mass units. Nitrogen is a gas that has the atomic number 7 and the chemical symbol N. There are 7 neutrons, 7 protons and 7 electrons in a nitrogen atom. Nitrogen also has stable isotopes, such as N-14 and N-15.
Daniel Rutherford discovered this non-metal element in 1772. Its name comes from the Greek words "nitron" and "genes," meaning "nitre forming." The Earth’s atmosphere contains about 78 percent of this element. To obtain nitrogen in pure form, liquefied air goes through a process called fractional distillation.
A main application for nitrogen is in the manufacture of ammonia. Ammonia is important for making substances like fertilizers, protective shielding in welding applications, refrigeration and explosives.