Nitrogen-16

Properties and data of the isotope ¹⁶N.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Nitrogen-16 is a radioisotope of the chemical element nitrogen, which has 9 neutrons in its atomic nucleus in addition to the element-specific 7 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 16. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁶N is exclusively for academic purposes.

The high-energy gamma emitter nitrogen-16 is technically relevant under certain conditions in nuclear facilities, such as nuclear power plants. For example, ¹⁶N is created from oxygen-containing materials through (n,p) reactions, for example from oxygen-16 in the cooling water of pressurized water or boiling water reactors [2]:

¹⁶O(n,p)¹⁶N.

In newer reactor types, there is a similar problem in systems that use fluoride-containing coolants. Here, nitrogen-16 is formed in an (n,α) reaction from fluorine-19 [3]:

¹⁹F(n,α)¹⁶N.

The latter nuclear reaction also led to the discovery of the isotope, which was reported in 1933 [1].

See also: List of individual Nitrogen isotopes (and general data sources).

General data

Name of the isotope:Nitrogen-16; N-16Symbol:¹⁶N or 167NMass number A:16 (= number of nucleons)Atomic number Z:7 (= number of protons)Neutrons N:9Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.2857142857143 (= neutron-proton ratio)Neutron excess (N-Z):2Isotopic mass:16.0061019(25) u (atomic weight of Nitrogen-16)Nuclide mass:16.0022619 u (calculated nuclear mass without electrons)Mass excess:5.68388 MeVMass defect:0.126657568 u (per nucleus)Nuclear binding energy:117.98076465 MeV (per nucleus)
7.37379779 MeV (average binding energy per nucleon)Separation energy:S_N = 2.4888(23) MeV (first neutron)
S_P = 11.4782(24) MeV (first proton)Half-life:7.13(2) sDecay constant λ:0.097215593346416 s^-1Specific activity α:3.659037480715 × 10⁺²¹ Bq g^-1
98892904884.197 Ci g^-1Spin and parity:
(nuclear angular momentum)2-Isobaric spin: 1Magnetic dipole moment:μ(μ_N) = 1.9856(11)Nuclear g-factor:g_l = 0.9928Mirror nucleus:Fluorine-16Year of discovery:1933

Radioactive Decay

Half-life T_½ = 7.13(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁶O	99.99846(5) %	10.4209(23) MeV	6.12863(4) MeV [67.0(6) %] 7.11515(14) MeV [4.9(4) %]
β^-, α	¹²C	0.00154(5) %	3.2590(23) MeV

Formation and radioactive decay of nitrogen-16

Parent Nuclides

Direct parent isotopes are: ¹⁶C, ¹⁷C.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^16mN	120.42(12) keV	5.25(6) μs	0-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 9) and isobaric (same nucleon number A = 16) with Nitrogen-16. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 9	Isobar A = 16
3	¹²Li
4	¹³Be	¹⁶Be
5	¹⁴B	¹⁶B
6	¹⁵C	¹⁶C
7	¹⁶N	¹⁶N
8	¹⁷O	¹⁶O
9	¹⁸F	¹⁶F
10	¹⁹Ne	¹⁶Ne
11	²⁰Na
12	²¹Mg
13	²²Al
14	²³Si
15	²⁴P