Fluorine-27

Properties and data of the isotope ²⁷F.

Contents

Fluorine-27 is a radioisotope of the chemical element fluorine, which has 18 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 27. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁷F is exclusively for academic purposes.

The first observation of the neutron rich instable isotope was first reported in 1981 in an experiment in which calcium-48 ions accelerated to 213 MeV per nucleon were fragmented on a Be target [1].

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

General data

Name of the isotope:Fluorine-27; F-27Symbol:²⁷F or 279FMass number A:27 (= number of nucleons)Atomic number Z:9 (= number of protons)Neutrons N:18Isotopic mass:27.026980(130) u (atomic weight of Fluorine-27)Nuclide mass:27.0220428 u (calculated nuclear mass without electrons)Mass excess:25.13171 MeVMass defect:0.199413776 u (per nucleus)Nuclear binding energy:185.75273586 MeV (per nucleus)
6.87973096 MeV (average binding energy per nucleon)Separation energy:S_N = 1.612(59) MeV (first neutron)
S_P = 16.817(204) MeV (first proton)Half-life:5.0(2) msDecay constant λ:138.62943611199 s^-1Specific activity α:3.092022191111 × 10⁺²⁴ Bq g^-1
83568167327327 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1981

Radioactive Decay

Half-life T_½ = 5.0(2) ms respectively 5.0 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	²⁷Ne	23(21) %	18.080(150) MeV
β^-, n	²⁶Ne	77(21) %	16.581(122) MeV
β^-, 2n	²⁵Ne	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 18) and isobaric (same nucleon number A = 27) with Fluorine-27. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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