Nitrogen-15
Properties and data of the isotope 15N.
The stable isotope nitrogen-14, at 0.3795%, represents the much smaller part of the natural terrestrial element nitrogen (for composition see below). The atomic nucleus of the nuclide consists of 8 neutrons and the element-specific 7 protons.
According to a report from 1929, 15N was first identified and thus discovered on the basis of the absorption spectrum recorded with an E1-Hilger spectrograph of a gaseous NO sample illuminated with the continuous light of a hydrogen lamp [1].
See also: list of Nitrogen isotopes.
General data
Name of the isotope:Nitrogen-15; N-15Symbol:15N or 157NMass number A:15 (= number of nucleons)Atomic number Z:7 (= number of protons)Neutrons N:8Isotopic mass:15.0001088983(6) u (atomic weight of Nitrogen-15)Nuclide mass:14.9962689 u (calculated nuclear mass without electrons)Mass excess:0.10144 MeVMass defect:0.1239856537 u (per nucleus)Nuclear binding energy:115.49189251 MeV (per nucleus)
7.6994595 MeV (average binding energy per nucleon)Separation energy:SN = 10.8332956(8) MeV (first neutron)
SP = 10.207425(4) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2-Isobaric spin: 1/2Magnetic dipole moment:μ(μN) = -0.28318884(5)Charge radius:2.6058(80) femtometer fmMirror nucleus:Oxygen-15Year of discovery:1929
Parent Nuclides
Direct parent isotopes are: 15O, 15C.
Occurrence
Comparison of the natural Nitrogen isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| Atomic Mass ma | 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 15N
Isotope:15N-NMRQuantity:0.3795 % [0.337 - 0.422 %]Spin:1/2-Nuclearmagnetic moment
μ/μN:-0.28318884(5)Gyromagnetic ratio γ:–2.71261804 · 107 rad T-1 s-1Nuclear g-factor:gl = -0.56637768Resonance frequency:v0 = 4.3173 at 1 TFrequency ratio:Ξ(15N) = 10.136767 %Relative Sensitivity:0.00104 (H0 = const.)
0.1014 (v0 = const.)
[related to 1H = 1.000]Reference compound:
(conditions)The recommended reference substance (IUPAC) is a solution of nitromethane (< 10 %) in purified chloroform-d. .In practice, however, pressurized liquid ammonia (NH3) is often used (δNH3 = δCH3NO2 + 380.5 ppm).
Both natural N nuclides - Nitrogen-14 and -15 - are NMR active, although 15N has a nucleus that is not very sensitive to 15NMR spectroscopy and only accounts for 0.3795% of natural samples.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 8) and isobaric (same nucleon number A = 15) with Nitrogen-15. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 8 | Isobar A = 15 |
2 | 10He | |
3 | 11Li | |
4 | 12Be | 15Be |
5 | 13B | 15B |
6 | 14C | 15C |
7 | 15N | 15N |
8 | 16O | 15O |
9 | 17F | 15F |
10 | 18Ne | 15Ne |
11 | 19Na | |
12 | 20Mg | |
13 | 21Al | |
14 | 22Si | |
External data and identifiers
Literature and References
[1] - S. M. Naudé:
An Isotope of Nitrogen, Mass 15.
In: Physical Review,34, 1498, (1929), DOI 10.1103/PhysRev.34.1498.
Last update: 2024-09-29
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