7
N
Nitrogen
Atomic Mass14.00674
Electron Configuration155 pm (Van der Waals)
Oxidation States4S°3/2
Year Discovered1772

Identifiers

Element NameNitrogen
Element SymbolN
InChIInChI=1S/N
InChIKeyQJGQUHMNIGDVPM-UHFFFAOYSA-N

Properties

Atomic Weight

[14.006 43, 14.007 28]

14.00674

14.01

[14.00643,14.00728]

Atomic Radius

Van der Waals Atomic Radius :155 pm (Van der Waals)

Empirical Atomic Radius :65pm (Empirical)

Covalent Atomic Radius :71(1) pm (Covalent)

Oxidation States

+5, +4, +3, +2, +1, -1, -2, -3

5, 4, 3, 2, 1, -1, -2, -3 ​(a strongly acidic oxide)

Ground Level

43/2

Ionization Energy

14.534 eV

14.53413 ± 0.00004 eV

Electronegativity

Pauling Scale Electronegativity :3.04(Pauling Scale)

Allen Scale Electronegativity :3.066(Allen Scale)

Electron Affinity

0eV

-0.21eV

Atomic Spectra

Lines Holdings

Levels Holdings

Physical Description

Gas

Element Classification

Non-metal

Element Period Number

2

Element Group Number

15 - Pnictogen

Density

0.0012506 grams per cubic centimeter

Melting Point

63.15 K (-210.00°C or -346.00°F)

-210.0°C

Boiling Point

77.36 K (-195.79°C or -320.44°F)

-195.795°C

Estimated Crustal Abundance

1.9×101 milligrams per kilogram

Estimated Oceanic Abundance

5×10-1 milligrams per liter

History

The name derives from the Latin nitrum and Greek nitron for "native soda" and genes for "forming". Nitrogen was discovered by the Scottish physician and chemist Daniel Rutherford in 1772.

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.

From the Latin word nitrum, Greek Nitron, native soda; and genes, forming. Nitrogen was discovered by chemist and physician Daniel Rutherford in 1772. He removed oxygen and carbon dioxide from air and showed that the residual gas would not support combustion or living organisms. At the same time there were other noted scientists working on the problem of nitrogen. These included Scheele, Cavendish, Priestley, and others. They called it "burnt" or" dephlogisticated air," which meant air without oxygen.

Historical Atomic Weights

Year Atomic Weight (uncertainty) [u] Reference
2009 [14.006 43, 14.007 28] https://doi.org/10.1351/PAC-REP-10-09-14
1999 14.0067(2) https://doi.org/10.1351/pac200173040667
1985 14.006 74(7) https://doi.org/10.1351/pac198658121677
1969 14.0067(1) https://doi.org/10.1351/pac197021010091
1961 14.0067 https://doi.org/10.1021/ja00881a001
1920 14.008 https://doi.org/10.1021/ja02233a600
1907 14.01 https://doi.org/10.1021/ja01956a001
1902 14.04 https://doi.org/10.1007/BF01370337

Historical Isotopic Abundances

Year Isotope Abundance (uncertainty) Reference
2013 14N [0.995 78, 0.996 63] https://doi.org/10.1515/pac-2015-0503
2013 15N [0.003 37, 0.004 22] https://doi.org/10.1515/pac-2015-0503
2001 14N 0.996 36(20) https://doi.org/10.1063/1.1836764
2001 15N 0.003 64(20) https://doi.org/10.1063/1.1836764
1997 14N 0.996 32(7) https://doi.org/10.1351/pac199870010217
1997 15N 0.003 68(7) https://doi.org/10.1351/pac199870010217
1981 14N 0.996 34(9) https://doi.org/10.1351/pac198355071119
1981 15N 0.003 66(9) https://doi.org/10.1351/pac198355071119
1975 14N 0.9964 https://doi.org/10.1351/pac197647010075
1975 15N 0.0036 https://doi.org/10.1351/pac197647010075

Users

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.

Sources

Nitrogen gas (N2) makes up 78.1% of the Earth’s air, by volume. The atmosphere of Mars, by comparison, is only 2.6% nitrogen. From an exhaustible source in our atmosphere, nitrogen gas can be obtained by liquefaction and fractional distillation. Nitrogen is found in all living systems as part of the makeup of biological compounds.

Compounds

Sodium nitrate (NaNO3) and potassium nitrate (KNO3) are formed by the decomposition of organic matter with compounds of these metals present. In certain dry areas of the world these saltpeters are found in quantity and are used as fertilizers. Other inorganic nitrogen compounds are nitric acid (HNO3), ammonia (NH3), the oxides (NO, NO2, N2O4, N2O), cyanides (CN-), etc.

The nitrogen cycle is one of the most important processes in nature for living organisms. Although nitrogen gas is relatively inert, bacteria in the soil are capable of “fixing” the nitrogen into a usable form (as a fertilizer) for plants. In other words, Nature has provided a method to produce nitrogen for plants to grow. Animals eat the plant material where the nitrogen has been incorporated into their system, primarily as protein. The cycle is completed when other bacteria convert the waste nitrogen compounds back to nitrogen gas. Nitrogen is crucial to life, as it is a component of all proteins.

See more information at the Nitrogen compound page.

Element Forms

CID Name Formula SMILES Molecular Weight
57370662 nitrogen N [N] 14.007
91867648 nitrogen-13 N [13N] 13.005739
57347672 nitrogen(1+) N+ [N+] 14.007
59197653 nitrogen(1-) N- [N-] 14.007

Isotopes

Stable Isotope Count2

Isotopes in Biology

Isotopic fractionation can cause the isotope-amount ratio n(15N)/n(14N) to increase systematically through food chains through assimilation of nitrogen compounds in biomolecules such as proteins. When lower-order organisms are ingested by higher-order organisms, 15N may be selectively retained and 14N may be selectively excreted such that higher-order organisms tend to have higher n(15N)/n(14N) ratios than their food sources. Isotopic fractionation occurs as a result of assimilation, storage, and excretion of proteins and other nitrogen compounds. Biologists can use isotope-amount ratio n(15N)/n(14N) measurements to test hypotheses about predator-prey relations and detect disruptions to trophic structure of ecosystems that might be caused by toxic contaminants, invasive species, or harvesting of organisms. Similar principles are used to detect differences in diets among animals, including humans, both today and in the distant past [79], [80], [81].

Artificially enriched 15N tracers are used to study movement and transformation of nitrogen in biological and environmental systems, such as the uptake and loss of nitrogen fertilizers by crops (Fig. IUPAC.7.1). A common experiment involves introducing an isotopically labeled compound into the environment and then analyzing various samples taken from the environment for the presence of the enriched isotope to determine where the labeled compound moved and whether it transformed into other compounds (Fig. IUPAC.7.2). Artificially enriched 15N is used to study uptake and dispersal of nitrogen in feed supplies used in food production industries such as aquaculture [82].

Fig. IUPAC.7.1: Variation in nitrogen stable isotopes has been used to track fertilizer nitrogen into plants, soils, and infiltrating groundwater in experiments to improve agricultural efficiency and reduce impacts on the environment. This aerial photograph shows experimental agricultural fields where different amounts of excess nitrogen from fertilizer and plant residues can be found in groundwater. (Photo Source: Böhlke, J.K., U.S. Geological Survey).

Fig. IUPAC.7.2: Tracer experiments with the stable isotope ¹⁵N have been used to track excess dissolved nitrate in groundwater and streams and to determine to what extent the dissolved nitrate is removed by natural processes, such as conversion to harmless N2 gas before entering nitrogen-sensitive ecosystems [83]. (Photo Source: Böhlke, J.K., U.S. Geological Survey).

[79] P. L. Koch, M. L. Fogel, N. Tuross. “Tracing the diets of fossil animals using stable isotopes”, in Stable Isotopes in Ecology and Environmental Science, K. Lajtha and R. H. Michener (Eds.), Blackwell Scientific Publications, Boston (1994).
[80] J. P. Montoya. “Nitrogen isotope fractionation in the modern ocean: implications for the sedimentary record”, in Carbon Cycling in the Glacial Ocean: Constraints on the Ocean’s Role in Global Change. NATO ASI Series (Series I: Global Environmental Change), R. Zahn, T. F. Pedersen, M. A. Kaminski, L. Labeyrie (Eds.), vol. 17. Springer, Berlin, Heidelberg (1994).
[81] R. E. M. Hedges, L. M. Reynard. J. Archaeolog. Sci.34, 1240 (2007).
[82] M. A. Burford, N. P. Preston, P. M. Glibert, W. C. Dennison. Aquaculture206, 199 (2002).
[83] J. K. Böhlke, R. C. Antweiler, J. W. Harvey, A. E. Laursen, L. K. Smith, R. L. Smith, M. A. Voytek. Biogeochemistry93, 117 (2009).

Isotopes in Earth/Planetary Science

The stable isotopes of nitrogen are subject to isotopic fractionation by physical, chemical, and biological processes. Variations in the isotope-amount ratio n(15N)/n(14N) are substantial (Fig. IUPAC.7.3) and commonly are used to study Earth-system processes, especially those related to biology because nitrogen is a major nutrient for growth [84]. For example, isotope fractionation occurs when dissolved solutes, such as nitrate (NO3 -), are transformed to more reduced compounds (i.e. nitrogen gas) because nitrate with higher 14N abundances tends to be more readily broken down. This leaves the residual unreacted nitrate with a higher n(15N)/n(14N) ratio than the initial ratio prior to reaction. Changes in the isotopic composition of biologically reactive compounds can be used to detect such reactions in aquatic environments, which are important mechanisms for removing reactive contaminants like nitrate [85], [86].

Variations in the isotope-amount ratio n(15N)/n(14N) are used to determine sources of nitrogen contamination in the atmosphere, oceans, groundwater, and rivers, where the isotopic composition of a contaminant molecule preserves evidence of the nitrogen sources and processes involved in its creation. An example is nitrate derived from artificial fertilizer, manure, power-plant emissions, or natural sources [87], [88], [89].

Artificially enriched 15N tracers have been used to determine rates of movement and natural remediation of nitrogen-bearing contaminants in aquifers and rivers [83], [90].

Fig. IUPAC.7.3: Variation in atomic weight with isotopic composition of selected nitrogen-bearing materials (modified from [13], [17]).

[13] M. W. Wieser, T. B. Coplen. Pure Appl Chem.83, 359 (2011).
[17] T. B. Coplen, J. A. Hopple, J. K. Böhlke, H. S. Peiser, S. E. Rieder, H. R. Krouse, K. J. R. Rosman, T. Ding, R. D. Vocke, K. Revesz, A. Lamberty, P. D. P. Taylor, P. D. Bièvre. United States Geological Survey Water-Resources Investigations Report, 01-4222, (2002).
[83] J. K. Böhlke, R. C. Antweiler, J. W. Harvey, A. E. Laursen, L. K. Smith, R. L. Smith, M. A. Voytek. Biogeochemistry93, 117 (2009).
[84] Stable Isotopes in Ecology and Environmental Science: 2nd Edition, ed. R. Michener and K. Lajtha, p. 566, Blackwell Publishing Ltd., Malden, MA (2007).
[85] J. Granger, D. M. Sigman, M. F. Lehmann, P. D. Tortell. Limnol. Oceanogr.53, 2533 (2008).
[86] A. Mariotti, A. Landreau, B. Simon. Limnol. Oceanogr.52, 1869 (1988).
[87] T. H. E. Heaton. Chem. Geol.59, 87 (1986).
[88] C. Kendall, R. Aravena. “Nitrate isotopes in groundwater systems”, in Environmental Tracers in Subsurface Hydrology, P. G. Cook and A. L. Herczeg (Eds.), Kluwer Academic Publishers, Boston (2000).
[89] B. Mayer, E. W. Boyer, C. Goodale, N. A. Jaworski, N. Van Breemen, R. W. Howarth, S. P. Seitzinger, G. Billen, K. Lajtha, K. J. Nadelhoffer, D. Van Dam, L. J. Hetling, M. Nosal, K. Paustian. Biogeochemistry57 & 58, 171 (2002).
[90] R. L. Smith, J. K. Böhlke, S. P. Garabedian, K. M. Revesz, T. Yoshinari. Water Resour. Res.40, 1 (2004).

Isotopes in Forensic Science and Anthropology

Stable hydrogen, carbon, and nitrogen isotopic compositions are used to determine the origin of pseudoephedrine from seized methyl-amphetamine made from the pseudoephedrine (drug used as a nasal decongestant or as a stimulant) [91].

[91] H. Salouros, G. J. Sutton, J. Howes, D. B. Hibbert, M. Collins. Anal. Chem.85, 9400 (2013).

Isotope Mass and Abundance

Isotope Atomic Mass (uncertainty) [u] Abundance (uncertainty)
14N 14.003 074 004(2) [0.995 78, 0.996 63]
15N 15.000 108 899(4) [0.003 37, 0.004 22]
Isotope Atomic Mass (uncertainty) [u] Abundance (uncertainty)
14N 14.00307400443(20) 0.99636(20)
15N 15.00010889888(64) 0.00364(20)

Atomic Mass, Half Life, and Decay

Nuclide Atomic Mass and Uncertainty [u] Half Life and Uncertainty Discovery Year Decay Modes, Intensities and Uncertainties [%]
10N 10.041653540 ± 0.000429417 143 ys ± 36 2002 p ?
11N 11.026157593 ± 0.000005368 585 ys ± 7 1974 p=100%
11Nm 11.026157593 ± 0.000005368 690 ys ± 80 1974 p=100%
12N 12.018613180 ± 0.000001073 11.000 ms ± 0.016 1949 β+=100%; β+α=1.93±0.4%
13N 13.005738609 ± 0.000000289 9.965 m ± 0.004 1934 β+=100%
14N 14.00307400425 ± 0.00000000024 Stable 1920 IS=99.6205±24.7%
15N 15.00010889827 ± 0.00000000062 Stable 1929 IS=0.3795±24.7%
16N 16.006101925 ± 0.00000247 7.13 s ± 0.02 1933 β-=100%; β-α=0.00154±0.5%
16Nm 16.006101925 ± 0.00000247 5.25 us ± 0.06 1957 IT≈100%; β-=0.000389±2.5%
17N 17.008448876 ± 0.000016103 4.173 s ± 0.004 1949 β-=100%; β-n=95.1±0.7%; β-α=0.0025±0.4%
18N 18.014077563 ± 0.000019935 619.2 ms ± 1.9 1964 β-=100%; β-n=7.0±1.5%; β-α=12.2±0.6%; β-2n ?
19N 19.017022389 ± 0.00001761 336 ms ± 3 1968 β-=100%; β-n=41.8±0.9%
20N 20.023367295 ± 0.000084696 136 ms ± 3 1969 β-=100%; β-n=42.9±1.4%; β-2n ?
21N 21.027087573 ± 0.000143906 85 ms ± 5 1970 β-=100%; β-n=87±0.3%; β-2n ?
22N 22.034100918 ± 0.00022306 23 ms ± 3 1979 β-=100%; β-n=34±0.3%; β-2n=12±0.3%
23N 23.039421000 ± 0.0004515 13.9 ms ± 1.4 1985 β-=100%; β-n=42±0.6%; β-2n=8±0.4%; β-3n<3.4%
24N 24.050390 ± 0.00043 [Estimated] Not-specified <52ns n ?
25N 25.060100 ± 0.00054 [Estimated] Not-specified <260ns n ?; 2n ?; β- ?

Information Sources

  1. 1.  PubChem
  2. 2.  Atomic Mass Data Center (AMDC), International Atomic Energy Agency (IAEA)
  3. 3.  IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW)
  4. 4.  Jefferson Lab, U.S. Department of Energy
    LICENSE
    Please see citation and linking information https https://www.jlab.org/privacy-and-security-notice
  5. 5.  Los Alamos National Laboratory, U.S. Department of Energy
  6. 6.  NIST Physical Measurement Laboratory
  7. 7.  IUPAC Periodic Table of the Elements and Isotopes (IPTEI)
    LICENSE
    Copyright (c) 2020 International Union of Pure and Applied Chemistry. The International Union of Pure and Applied Chemistry (IUPAC) contribution within Pubchem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc-nd/4.0/
  8. 8.  PubChem Elements
    Nitrogen

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