Nitrogen-9

Properties and data of the isotope ⁹N.

Content

Nitrogen-9 is a hypothetical radioisotope of the chemical element nitrogen, which, in addition to the element-specific 7 protons, has 2 neutrons in the atomic nucleus, resulting in the mass number 9. The extremely short-lived, unstable and therefore radioactive nuclide, which can only be produced artificially, has no practical significance; The study of ⁹N is exclusively for academic purposes.

In October 2023, researchers reported for the first time that they had found evidence for the existence of this exotic atomic nucleus [1]. The extremely proton-rich and neutron-poor nuclide basically consists of a helium-4 nucleus (α particle) surrounded by 5 protons ; This state decays almost at the moment of its creation and releases the 5 protons and the ⁴He nucleus.

The nucleus synthesis was achieved by bombarding a 1 mm thick film made of beryllium with a particle beam of nitrogen-13 nuclei, whereby the ⁹N nuclei appeared as fragments of oxygen.

The following data are therefore only estimates!

General data

Name of the isotope:Nitrogen-9; N-9Symbol:⁹N or 97NMass number A:9 (= number of nucleons)Atomic number Z:7 (= number of protons)Neutrons N:2Isotopic mass:9 u (atomic weight of Nitrogen-9)Nuclide mass:8.99616 u (calculated nuclear mass without electrons)Mass excess:0 MeVMass defect:0.072105056 u (per nucleus)Nuclear binding energy:67.16542703 MeV (per nucleus)
7.46282523 MeV (average binding energy per nucleon)Half-life:< 1 asDecay constant λ:6.931471805599 × 10⁺¹⁷ s^-1Specific activity α:4.638033286666 × 10⁺⁴⁰ Bq g^-1
1.253522509909 × 10⁺³⁰ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2022

Radioactive Decay

Half-life T_½ = < 1 as respectively 1 × 10^-18 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
5p	⁴He

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 2) and isobaric (same nucleon number A = 9) with Nitrogen-9. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 2	Isobar A = 9
1	³H
2	⁴He	⁹He
3	⁵Li	⁹Li
4	⁶Be	⁹Be
5	⁷B	⁹B
6	⁸C	⁹C
7	⁹N	⁹N

Literature and References

[1] - R. J. Charity, J. Wylie, S. M. Wang, T. B. Webb et al.:
Strong Evidence for ⁹N and the Limits of Existence of Atomic Nuclei.
In: Physical Review Letters, 131, 172501, (2023), DOI 10.1103/PhysRevLett.131.172501.