Fluorine-29

Properties and data of the isotope ²⁹F.

Contents

Fluorine-29 is a radioisotope of the chemical element fluorine, which has 20 neutrons in its atomic nucleus in addition to the element-specific 9 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 29. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁹F is exclusively for academic purposes and experimental research.

The discovery of the neutron-rich unstable isotope was first reported in 1989. Fluorine-29 was observed when a tantalum sample was irradiated with calcium-48 with an energy of 55 MeV/u.

General data

Name of the isotope:Fluorine-29; F-29Symbol:²⁹F or 299FMass number A:29 (= number of nucleons)Atomic number Z:9 (= number of protons)Neutrons N:20Isotopic mass:29.043100(560) u (atomic weight of Fluorine-29)Nuclide mass:29.0381628 u (calculated nuclear mass without electrons)Mass excess:40.14739 MeVMass defect:0.200623608 u (per nucleus)Nuclear binding energy:186.87968711 MeV (per nucleus)
6.44412714 MeV (average binding energy per nucleon)Separation energy:S_N = 1.325(539) MeV (first neutron)
S_P = 19.219(874) MeV (first proton)Half-life:0.0025(3) sDecay constant λ:277.25887222398 s^-1Specific activity α:5.757558562758 × 10⁺²⁴ Bq g^-1
1.556096908853 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1989

Radioactive Decay

Half-life T_½ = 0.0025(3) s respectively 2.5 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	²⁹Ne	40(40) %	21.750(550) MeV
β^-, n	²⁸Ne	60(40) %	20.779(540) MeV
β^-, 2n	²⁷Ne	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 20) and isobaric (same nucleon number A = 29) with Fluorine-29. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 20	Isobar A = 29
8	²⁸O
9	²⁹F	²⁹F
10	³⁰Ne	²⁹Ne
11	³¹Na	²⁹Na
12	³²Mg	²⁹Mg
13	³³Al	²⁹Al
14	³⁴Si	²⁹Si
15	³⁵P	²⁹P
16	³⁶S	²⁹S
17	³⁷Cl	²⁹Cl
18	³⁸Ar
19	³⁹K
20	⁴⁰Ca
21	⁴¹Sc
22	⁴²Ti
23	⁴³V
24	⁴⁴Cr
25	⁴⁵Mn
26	⁴⁶Fe
27	⁴⁷Co
28	⁴⁸Ni

External data and identifiers

Adopted Levels, Gammas:NuDat 29F

Literature and References

[1] - D. Guillemaud-Mueller, Yu. E. Penionzhkevich, R. Anne et al.:
Observation of new neutron rich nuclei ²⁹F, ^35,36Mg, ^38,39Al, ^40,41Si, ^43,44P, ^45-47S, ^46-49Cl, and ^49-51Ar from the interactions of 55 MeV/u ⁴⁸Ca+Ta.
In: Z. Physik A - Atomic Nuclei, 332, (1989), DOI 10.1007/BF01289774.

[2] - L. Fortunato, J. Casal, W. Horiuchi, Jagjit Singh, A. Vitturi:
The ²⁹F nucleus as a lighthouse on the coast of the island of inversion.
In: Communications Physics, 3, 132, (2020), DOI 10.1038/s42005-020-00402-5.

[3] - Shu-Yuan Zhai, Xue-Neng Cao, Jian-You Guo:
Research on the deformed halo in ²⁹F with a complex momentum representation method.
In: Journal of Physics G, 49, 065101, (2022), DOI 10.1088/1361-6471/ac5dfd.