Fluorine-25

Properties and data of the isotope ²⁵F.

Contents

Fluorine-25 is a radioisotope of the chemical element fluorine, which has 16 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 25. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁵F is exclusively for academic purposes and experimental research.

The neutron rich instable nuclide was discovered by irradiating thorium-232 with neon-22 ions accelerated to 174 MeV [1].

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

General data

Name of the isotope:Fluorine-25; F-25Symbol:²⁵F or 259FMass number A:25 (= number of nucleons)Atomic number Z:9 (= number of protons)Neutrons N:16Isotopic mass:25.012170(100) u (atomic weight of Fluorine-25)Nuclide mass:25.0072328 u (calculated nuclear mass without electrons)Mass excess:11.33628 MeVMass defect:0.196893944 u (per nucleus)Nuclear binding energy:183.40552747 MeV (per nucleus)
7.3362211 MeV (average binding energy per nucleon)Separation energy:S_N = 4.282(137) MeV (first neutron)
S_P = 14.455(191) MeV (first proton)Half-life:80(9) msDecay constant λ:8.6643397569993 s^-1Specific activity α:2.08711497 × 10⁺²³ Bq g^-1
5640851294594.6 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1970

Radioactive Decay

Half-life T_½ = 80(9) ms respectively 8.0 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	²⁵Ne	76.9(45) %	13.370(100) MeV
β^-, n	²⁴Ne	23.1(45) %	9.214(96) MeV
β^-, 2n	²³Ne	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 16) and isobaric (same nucleon number A = 25) with Fluorine-25. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 16	Isobar A = 25
5	²¹B
6	²²C
7	²³N	²⁵N
8	²⁴O	²⁵O
9	²⁵F	²⁵F
10	²⁶Ne	²⁵Ne
11	²⁷Na	²⁵Na
12	²⁸Mg	²⁵Mg
13	²⁹Al	²⁵Al
14	³⁰Si	²⁵Si
15	³¹P	²⁵P
16	³²S
17	³³Cl
18	³⁴Ar
19	³⁵K
20	³⁶Ca
21	³⁷Sc
22	³⁸Ti

External data and identifiers

Adopted Levels, Gammas:NuDat 25F

Literature and References

[1] - A. G. Artukh et al.:
New isotopes ²¹N, ²³O, ²⁴O and ²⁵F, produced in nuclear reactions with heavy ions.
In: Physics Letters B, 32(1), (1970), DOI 10.1016/0370-2693(70)90332-1.

[2] - T. L. Tang et al.:
How Different is the Core of ²⁵F from ²⁴O_g.s.?.
In: Physical Review Letters,124, 212502, (2020), DOI 10.1103/PhysRevLett.124.212502.

[3] - A. O. Macchiavelli et al.:
Core of ²⁵F in the rotational model.
In: Physical Review C, 102, 041301(R), (2020), DOI 10.1103/PhysRevC.102.041301.