The Element Nitrogen
Atomic Number: 7
Atomic Weight: 14.00674
Melting Point: 63.15 K (-210.00°C or -346.00°F)
Boiling Point: 77.36 K (-195.79°C or -320.44°F)
Density: 0.0012506 grams per cubic centimeter
Phase at Room Temperature: Gas
Element Classification: Non-metal
Period Number: 2
Group Number: 15
Group Name: Pnictogen
What's in a name? From the Greek words nitron and genes, which together mean "saltpetre forming."
Say what? Nitrogen is pronounced as NYE-treh-gen.
History and Uses:
Nitrogen was discovered by the Scottish physician Daniel Rutherford in 1772. It is the fifth most abundant element in the universe and makes up about 78% of the earth's atmosphere, which contains an estimated 4,000 trillion tons of the gas. Nitrogen is obtained from liquefied air through a process known as fractional distillation.
The largest use of nitrogen is for the production of ammonia (NH3). Large amounts of nitrogen are combined with hydrogen to produce ammonia in a method known as the Haber process. Large amounts of ammonia are then used to create fertilizers, explosives and, through a process known as the Ostwald process, nitric acid (HNO3).
Nitrogen gas is largely inert and is used as a protective shield in the semiconductor industry and during certain types of welding and soldering operations. Oil companies use high pressure nitrogen to help force crude oil to the surface. Liquid nitrogen is an inexpensive cryogenic liquid used for refrigeration, preservation of biological samples and for low temperature scientific experimentation. Jefferson Lab's Frostbite Theater features videos of many basic liquid nitrogen experiments, such as this one:
Estimated Crustal Abundance: 1.9×101 milligrams per kilogram
Estimated Oceanic Abundance: 5×10-1 milligrams per liter
Number of Stable Isotopes: 2 (View all isotope data)
Ionization Energy: 14.534 eV
Oxidation States: +5, +4, +3, +2, +1, -1, -2, -3