Nitrogen

  • nitrogen, 7n
    liquidnitrogen.jpg
    nitrogen
    appearancecolorless gas, liquid or solid
    standard atomic weight ar, std(n)[14.0064314.00728] conventional: 14.007
    nitrogen in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson


    n

    p
    carbonnitrogenoxygen
    atomic number (z)7
    groupgroup 15 (pnictogens)
    periodperiod 2
    blockp-block
    element category  reactive nonmetal
    electron configuration[he] 2s2 2p3
    electrons per shell2, 5
    physical properties
    phase at stpgas
    melting point(n2) 63.15 k ​(−210.00 °c, ​−346.00 °f)
    boiling point(n2) 77.355 k ​(−195.795 °c, ​−320.431 °f)
    density (at stp)1.2506 g/l[1] at 0 °c, 1013 mbar
    when liquid (at b.p.)0.808 g/cm3
    triple point63.151 k, ​12.52 kpa
    critical point126.21 k, 3.39 mpa
    heat of fusion(n2) 0.72 kj/mol
    heat of vaporisation(n2) 5.56 kj/mol
    molar heat capacity(n2) 29.124 j/(mol·k)
    vapour pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 37 41 46 53 62 77
    atomic properties
    oxidation states−3, −2, −1, +1, +2, +3, +4, +5 (a strongly acidic oxide)
    electronegativitypauling scale: 3.04
    ionisation energies
    • 1st: 1402.3 kj/mol
    • 2nd: 2856 kj/mol
    • 3rd: 4578.1 kj/mol
    • (more)
    covalent radius71±1 pm
    van der waals radius155 pm
    color lines in a spectral range
    spectral lines of nitrogen
    other properties
    natural occurrenceprimordial
    crystal structurehexagonal
    hexagonal crystal structure for nitrogen
    speed of sound353 m/s (gas, at 27 °c)
    thermal conductivity25.83×10−3 w/(m·k)
    magnetic orderingdiamagnetic
    cas number17778-88-0
    7727-37-9 (n2)
    history
    discoverydaniel rutherford (1772)
    named byjean-antoine chaptal (1790)
    main isotopes of nitrogen
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    13n syn 9.965 min ε 13c
    14n 99.6% stable
    15n 0.4% stable
    category category: nitrogen
    | references

    nitrogen is the chemical element with the symbol n and atomic number 7. it was first discovered and isolated by scottish physician daniel rutherford in 1772. although carl wilhelm scheele and henry cavendish had independently done so at about the same time, rutherford is generally accorded the credit because his work was published first. the name nitrogène was suggested by french chemist jean-antoine-claude chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. antoine lavoisier suggested instead the name azote, from the greek ἀζωτικός "no life", as it is an asphyxiant gas; this name is instead used in many languages, such as french, russian, romanian and turkish, and appears in the english names of some nitrogen compounds such as hydrazine, azides and azo compounds.

    nitrogen is the lightest member of group 15 of the periodic table, often called the pnictogens. the name comes from the greek πνίγειν "to choke", directly referencing nitrogen's asphyxiating properties. it is a common element in the universe, estimated at about seventh in total abundance in the milky way and the solar system. at standard temperature and pressure, two atoms of the element bind to form dinitrogen, a colourless and odorless diatomic gas with the formula n2. dinitrogen forms about 78% of earth's atmosphere, making it the most abundant uncombined element. nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (dna and rna) and in the energy transfer molecule adenosine triphosphate. the human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. the nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere.

    many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. the extremely strong triple bond in elemental nitrogen (n≡n), the second strongest bond in any diatomic molecule after carbon monoxide (co),[2] dominates nitrogen chemistry. this causes difficulty for both organisms and industry in converting n2 into useful compounds, but at the same time means that burning, exploding, or decomposing nitrogen compounds to form nitrogen gas releases large amounts of often useful energy. synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems.

    apart from its use in fertilisers and energy-stores, nitrogen is a constituent of organic compounds as diverse as kevlar used in high-strength fabric and cyanoacrylate used in superglue. nitrogen is a constituent of every major pharmacological drug class, including antibiotics. many drugs are mimics or prodrugs of natural nitrogen-containing signal molecules: for example, the organic nitrates nitroglycerin and nitroprusside control blood pressure by metabolizing into nitric oxide. many notable nitrogen-containing drugs, such as the natural caffeine and morphine or the synthetic amphetamines, act on receptors of animal neurotransmitters.

  • history
  • properties
  • chemistry and compounds
  • occurrence
  • production
  • applications
  • safety
  • see also
  • references
  • bibliography
  • external links

Nitrogen, 7N
Liquidnitrogen.jpg
Nitrogen
Appearancecolorless gas, liquid or solid
Standard atomic weight Ar, std(N)[14.0064314.00728] conventional: 14.007
Nitrogen in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


N

P
carbonnitrogenoxygen
Atomic number (Z)7
Groupgroup 15 (pnictogens)
Periodperiod 2
Blockp-block
Element category  Reactive nonmetal
Electron configuration[He] 2s2 2p3
Electrons per shell2, 5
Physical properties
Phase at STPgas
Melting point(N2) 63.15 K ​(−210.00 °C, ​−346.00 °F)
Boiling point(N2) 77.355 K ​(−195.795 °C, ​−320.431 °F)
Density (at STP)1.2506 g/L[1] at 0 °C, 1013 mbar
when liquid (at b.p.)0.808 g/cm3
Triple point63.151 K, ​12.52 kPa
Critical point126.21 K, 3.39 MPa
Heat of fusion(N2) 0.72 kJ/mol
Heat of vaporisation(N2) 5.56 kJ/mol
Molar heat capacity(N2) 29.124 J/(mol·K)
Vapour pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 37 41 46 53 62 77
Atomic properties
Oxidation states−3, −2, −1, +1, +2, +3, +4, +5 (a strongly acidic oxide)
ElectronegativityPauling scale: 3.04
Ionisation energies
  • 1st: 1402.3 kJ/mol
  • 2nd: 2856 kJ/mol
  • 3rd: 4578.1 kJ/mol
  • (more)
Covalent radius71±1 pm
Van der Waals radius155 pm
Color lines in a spectral range
Spectral lines of nitrogen
Other properties
Natural occurrenceprimordial
Crystal structurehexagonal
Hexagonal crystal structure for nitrogen
Speed of sound353 m/s (gas, at 27 °C)
Thermal conductivity25.83×10−3 W/(m·K)
Magnetic orderingdiamagnetic
CAS Number17778-88-0
7727-37-9 (N2)
History
DiscoveryDaniel Rutherford (1772)
Named byJean-Antoine Chaptal (1790)
Main isotopes of nitrogen
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
13N syn 9.965 min ε 13C
14N 99.6% stable
15N 0.4% stable
Category Category: Nitrogen
| references

Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name azote, from the Greek ἀζωτικός "no life", as it is an asphyxiant gas; this name is instead used in many languages, such as French, Russian, Romanian and Turkish, and appears in the English names of some nitrogen compounds such as hydrazine, azides and azo compounds.

Nitrogen is the lightest member of group 15 of the periodic table, often called the pnictogens. The name comes from the Greek πνίγειν "to choke", directly referencing nitrogen's asphyxiating properties. It is a common element in the universe, estimated at about seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bind to form dinitrogen, a colourless and odorless diatomic gas with the formula N2. Dinitrogen forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere.

Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The extremely strong triple bond in elemental nitrogen (N≡N), the second strongest bond in any diatomic molecule after carbon monoxide (CO),[2] dominates nitrogen chemistry. This causes difficulty for both organisms and industry in converting N2 into useful compounds, but at the same time means that burning, exploding, or decomposing nitrogen compounds to form nitrogen gas releases large amounts of often useful energy. Synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems.

Apart from its use in fertilisers and energy-stores, nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric and cyanoacrylate used in superglue. Nitrogen is a constituent of every major pharmacological drug class, including antibiotics. Many drugs are mimics or prodrugs of natural nitrogen-containing signal molecules: for example, the organic nitrates nitroglycerin and nitroprusside control blood pressure by metabolizing into nitric oxide. Many notable nitrogen-containing drugs, such as the natural caffeine and morphine or the synthetic amphetamines, act on receptors of animal neurotransmitters.