Fluorine-25

Properties and data of the isotope ²⁵F.

Content

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:25.01217(10) 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 = 4.28(14) MeV (first neutron)
S_P = 14.46(19) 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	γ energy (intensity)
β^-	²⁵Ne	76.9(45) %	13.42331 MeV
β^-, n	²⁴Ne	23.1(45) %	9.2438 MeV

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.

OZ	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