Nitrogen-14

Properties and data of the isotope ¹⁴N.

Contents

General Data

Parent Nuclides

NMR Data

Isotones und Isobares

Literature

The stable isotope nitrogen-14 represents the majority of the natural terrestrial element nitrogen at 99.62% (for composition see below). The atomic nucleus of the nuclide ¹⁴ N consists of 7 neutrons and the element-specific 7 protons; ¹⁴N is one of the few stable isotopes that has an odd number of both protons and neutrons.

The origin of nitrogen-14 is thought to lie in stellar nucleosynthesis - specifically in the Bethe-Weizsäcker cycle, also called the CNO cycle for the three resulting elements C, N and O.

Nitrogen-14 as a separate isotope was identified in 1920 based on its mass spectrometric properties [1].

General data

Name of the isotope:Nitrogen-14; N-14Symbol:¹⁴N or 147NMass number A:14 (= number of nucleons)Atomic number Z:7 (= number of protons)Neutrons N:7Isotopic mass:14.003074004251(241) u (atomic weight of Nitrogen-14)Nuclide mass:13.999234 u (calculated nuclear mass without electrons)Mass excess:2.86342 MeVMass defect:0.112355631749 u (per nucleus)Nuclear binding energy:104.65859684 MeV (per nucleus)
7.47561406 MeV (average binding energy per nucleon)Separation energy:S_N = 10.55338(27) MeV (first neutron)
S_P = 7.55056(0) MeV (first proton)Cross section:σ(n.γ) = die (thermal neutron capture cross-section)Half-life:stableSpin and parity:
(nuclear angular momentum)1+Isobaric spin: 0Magnetic dipole moment:μ(μ_N) = +0.403573(2)Charge radius:2.5582(70) femtometer fmYear of discovery:1920

Parent Nuclides

Direct parent isotopes are: ¹⁴O, ¹⁴C.

Occurrence

Comparison of the natural Nitrogen isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Nitrogen Isotopic mixture	14.007 u	100 %
Isotope ¹⁴N	14.003074004251(241) u	99.6205 % [99.578 - 99.663 %]	stable	1+
Isotope ¹⁵N	15.0001088983(6) u	0.3795 % [0.337 - 0.422 %]	stable	1/2-

NMR data

Nuclear magnetic properties of the NMR active Nuclide ¹⁴N

Isotope:¹⁴N-NMRQuantity:99.6205 % [99.578 - 99.663 %]Spin:1+Nuclearmagnetic moment
μ/μ_N:+0.403573(2)Gyromagnetic ratio γ:1.9337792 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = 0.403573Quadrupole moment Q:0.02044(3) barn (100 fm²)Line width parameter (factor):l = 20.89 fm⁴Resonance frequency:v₀ = 3.0777 at 1 TFrequency ratio:Ξ(¹⁴N) = 7.226317 %Relative Sensitivity:0.00101 (H₀ = const.)
0.1928 (v₀ = const.)
[related to ¹H = 1.000]Reference compound:
(conditions)Solution of nitromethane in neat chloroform-d. Alternatively, liquid ammonia NH₃ is used; frequency ratio 7.223561 %.

Both natural N nuclides - nitrogen-15 and -14 - are NMR active, with ¹⁴N having a moderately sensitive nucleus for ¹⁴NMR spectroscopy, which often yields strongly broadened signals due to quadrupole interactions.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 7) and isobaric (same nucleon number A = 14) with Nitrogen-14. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 7	Isobar A = 14
2	⁹He
3	¹⁰Li
4	¹¹Be	¹⁴Be
5	¹²B	¹⁴B
6	¹³C	¹⁴C
7	¹⁴N	¹⁴N
8	¹⁵O	¹⁴O
9	¹⁶F	¹⁴F
10	¹⁷Ne
11	¹⁸Na
12	¹⁹Mg

External data and identifiers

CAS:1173020-41-1InChI Key:IJGRMHOSHXDMSA-IGMARMGPSA-NSMILES:[14N]PubChem:ID 71309542Adopted Levels, Gammas:NuDat 14N

Literature and References

[1] - F. W. Aston:
The Constitution of the Elements.
In: Nature, 106, 468, (1920), DOI 10.1038/106468a0.

[2] - Eddy Dib, Tzonka Mineva, Bruno Alonso:
Recent Advances in 14N Solid-State NMR.
In: Annual Reports on NMR Spectroscopy, 87, (2016), DOI 10.1016/bs.arnmr.2015.08.002.