Neon-18

Properties and data of the isotope ¹⁸Ne.

Contents

Neon-18 is a radioisotope of the chemical element neon, which has 8 neutrons in its atomic nucleus in addition to the element-specific 10 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 18. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁸Ne is exclusively for academic purposes and experimental research.

The unstable isotope was first described by J. D. Gow and Luis W. Alvarez in 1954 [1]. The discovery was made when fluorine-containing materials such as Teflon and crystalline lithium fluoride were irradiated with protons:

¹⁹F(p,2n)¹⁸Ne.

General data

Name of the isotope:Neon-18; Ne-18Symbol:¹⁸Ne or 1810NeMass number A:18 (= number of nucleons)Atomic number Z:10 (= number of protons)Neutrons N:8Isotopic mass:18.0057087(4) u (atomic weight of Neon-18)Nuclide mass:18.0002229 u (calculated nuclear mass without electrons)Mass excess:5.31762 MeVMass defect:0.141860948 u (per nucleus)Nuclear binding energy:132.1426219 MeV (per nucleus)
7.34125677 MeV (average binding energy per nucleon)Separation energy:S_N = 19.2542(5) MeV (first neutron)
S_P = 3.9231(4) MeV (first proton)Half-life:1664.20(47) msDecay constant λ:0.41650473534428 s^-1Specific activity α:1.393472325041 × 10⁺²² Bq g^-1
376614141903 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Isobaric spin: 1Charge radius:2.9714(76) femtometer fmMirror nucleus:Oxygen-18Year of discovery:1954

Radioactive Decay

Half-life T_½ = 1664.20(47) ms.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁸F	100 %	4.4445(6) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 8) and isobaric (same nucleon number A = 18) with Neon-18. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 8	Isobar A = 18
2	¹⁰He
3	¹¹Li
4	¹²Be
5	¹³B	¹⁸B
6	¹⁴C	¹⁸C
7	¹⁵N	¹⁸N
8	¹⁶O	¹⁸O
9	¹⁷F	¹⁸F
10	¹⁸Ne	¹⁸Ne
11	¹⁹Na	¹⁸Na
12	²⁰Mg	¹⁸Mg
13	²¹Al
14	²²Si