Celebrating 40 Years of ExcellencePhoto of SCCC studentsEducation That Works
Schenectady County Community College
Nitrogen - N

CAS: 7727-37-9
Description: Colorless, odorless, tasteless gas
Date of Discovery: 1772
Discoverer: Daniel Rutherford
Name Origin: Greek nitron, "native soda"; genes, "forming"

Atomic Number: 7
Number of Neutrons: 7
Atomic Mass: 14.00674(7) amu
Melting Point: -210.00 C
Boiling Point: -195.8 C
Density (293 K): 1.2506 g/cm3
liquid 0.808 g/cm3 @ -195.8 C
solid 1.026 g/cm3 @ -252 C
Atomic volume: 17.3 cm3/mol
Electrical resistivity:
Thermal conductivity: 0.0002598 W/cmK
Enthalpy of atomization: 472.79 kJ/mol
Enthalpy of vaporization: 2.7928 kJ/mol
Enthalpy of fusion: 0.3604 kJ/mol
Specific heat capacity: 1.04 J/gK
Energy levels: 2-5
Electron configuration: [He]2s22p3
Crystal Structure: Hexagonal
Atomic radius: 0.75
Covalent radius: 0.75
Oxidation States: -3, -2, -1, +1, +2, +3, +4, +5 (primarily +3 and +5)
Electronegativity, Pauling: 3.04
Electron affinity: not stable
First ionization energy: 14.534 eV
2nd ionization energy: 29.601 eV
3rd ionization energy: 47.448 eV
Polarizability: 1.10 10-24cm3
Isotope Natural Abundance Atomic Mass Half-life Decay Mode Spin
12N 12.018613 11.0 ms Beta Symbol+, Beta Symbol+ alpha symbol 1+
13N 13.0057386 9.97 m Beta Symbol- 1/2-
14N 99.634(9) 14.00307401 Stable 1+
15N 0.366(9) 15.0001090 Stable 1/2-
16N 16.006100 7.13 s Beta Symbol-; Beta Symbol-, alpha symbol 2-
17N 17.00845 4.17 sec Beta Symbol-, Beta Symbol- n; Beta Symbol- alpha symbol- 1/2-
18N 18.01408 0.62 s Beta Symbol- 1-
19N 19.01703 0.32 s Beta Symbol-
20N 20.02337 0.14 s Beta Symbol-
21N 21.0271 0.08 s
22N 22.0344 0.02 s
23N 23.0405
Discovered by Daniel Rutherford in 1772, but Scheele, Cavendish, Priestley, and others about the same time studied "burnt or dephlogisticated air," as air without oxygen was then called. Nitrogen makes up 78% of the air, by volume. The atmosphere of Mars, by comparison, is 2.6% nitrogen. The estimated amount of this element in our atmosphere is more than 4000 trillion tons. From this inexhaustible source it can be obtained by liquefaction and fractional distillation. Nitrogen molecules give the orange-red, blue-green, blue-violet, and deep violet shades to the aurora. The element is so inert that Lavoisier named it azote, meaning without life, yet its compounds are so active as to be most important in foods, poisons, fertilizers, and explosives. Nitrogen can be also easily prepared by heating a water solution of ammonium nitrite. Nitrogen, as a gas, is colorless, odorless, and a generally inert element. As a liquid it is also colorless and odorless, and is similar in appearance to water. Two allotropic forms of solid nitrogen exist, with the transition from the alpha to the beta form taking place at -237 C. When nitrogen is heated, it combines directly with magnesium, lithium, or calcium; when mixed with oxygen and subjected to electric sparks, it forms first nitric oxide (NO) and then the dioxide (NO2); when heated under pressure with a catalyst with hydrogen, ammonia (NH3) is formed (Haber process). The ammonia thus formed is of the utmost importance as it is used in fertilizers, and it can be oxidized to nitric acid (Ostwald process). The ammonia industry is the largest consumer of nitrogen. Large amounts of gas are also used by the electronics industry, which uses the gas as a blanketing medium during production of such components as transistors, diodes, etc. Large quantities of nitrogen are used in annealing, stainless steel and other steel mill products. The drug industry also uses large quantities. Nitrogen is used as a refrigerant both for the immersion freezing of food products and for transportation of foods. Liquid nitrogen is also used in missile work as a purge for components, insulators for space chambers, etc., and by the oil industry to build up great pressures in wells to force crude oil upward. Sodium and potassium nitrates are formed by the decomposition of organic matter with compounds of the metals present. In certain dry areas of the world these saltpeters are found in quantity. Ammonia, nitric acid, the nitrates, the five oxides (N2O, NO, N2O3, NO2, and N2O2), TNT, the cyanides, etc. are but a few of the important compounds. Natural nitrogen contains two isotopes, 14N and 15N. Ten other isotopes are known.

Adding Nitrous Oxide to your car
Chemical of the Week -- Ammonia
The Effect of Liquid Nitrogen on a Rose
Effects of Gas Pressure at Depth: Nitrogen Narcosis
Lost in the crowd: the story of nitric oxide
Nitrogen Chemistry in the Interstellar Medium
The Nitrogen Cycle
Nitrogen mineralization
Nitrogen Metabolism and the Urea Cycle
Nitrogen Oxides
Nitrogen and Plant Physiology
OSHA Chemical Sampling Information - Nitric Acid
Student Nitric Oxide Explorer Homepage
Water for Deserts - The Solar Fridge


Sources for the information on this website include:
Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998.