Nitrogen is all around us everywhere, as it is the transparent gas that makes up almost 75% of the Earth's atmosphere. Since pure nitrogen does not react easily, its liquid form can be used to freeze and preserve items such as blood and tissue samples.

Nitratine is one of the few nitrogen-rich minerals. Some useful nitrogen compounds can be manufactured by industrial processes. One family of nitrogen compounds is used in the manufacture of explosives, for example, TNT and nitroglycerin. These compounds explode because the bonds between the nitrogen atoms break very quickly. Nitrogen fuels, such as nitromethane, CH3NO2, are used in racing cars modified to undergo high acceleration (dragsters). Also, in internal combustion engines used for miniature cars, for example, in radio-controlled models.

The nitrogen-derived compound hydrazine, H2N-NH2, is used in spacecraft propellants. Some nitrogen compounds are used in dyes and glues. An industrial method called the Haber process, converts nitrogen and hydrogen gas into ammonia, a liquid commonly used to produce nitrogen fertilizers.

Summary of properties (N)

Atomic weight[14.00643, 14.00728]
Discoverer (year)Rutherford, Daniel (1772)
Natural formgas (N2)
Electron configuration[He] 2s2 2p3
Melting point (ºC)-210
Boiling point (ºC)-196
Abundance in earth's crust (ppm)19
Isotope (abundance)14N (99.636), 15N (0.364)
Density g/cm31.25
Van der Waals radius (pm)155
Covalent radius (pm)71
Electronegativity (Pauling)3.04
Vaporization enthalpy (kJ/mol)5.57
Enthalpy of fusion (kJ/mol)0.71
Specific heat capacity (J/g·K) at 25ºC and 1 atm1.04
Thermal conductivity (W/cm·K) at 25ºC and 1 atm<0.001 (N2)
Oxidation state+5, +4, +3, +2, +1, -1, -2, -3
Electron affinity (eV)unstable ion
1st Ionization potential (eV)14.5341

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