Neon-28

Properties and data of the isotope ²⁸Ne.

Contents

Neon-28 is a radioisotope of the chemical element neon, which has 18 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 28. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁸Ne is exclusively for academic purposes and experimental research.

The first observation of the neutron-rich nuclide was reported in 1979: ²⁸Ne was identified as the product of the fragmentation of a beam of argon-40 ions (205 MeV/nucleon) on a carbon target [1].

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

General data

Name of the isotope:Neon-28; Ne-28Symbol:²⁸Ne or 2810NeMass number A:28 (= number of nucleons)Atomic number Z:10 (= number of protons)Neutrons N:18Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.8 (= neutron-proton ratio)Neutron excess (N-Z):8Isotopic mass:28.012130(140) u (atomic weight of Neon-28)Nuclide mass:28.0066442 u (calculated nuclear mass without electrons)Mass excess:11.29902 MeVMass defect:0.222088808 u (per nucleus)Nuclear binding energy:206.87439212 MeV (per nucleus)
7.38837115 MeV (average binding energy per nucleon)Separation energy:S_N = 3.822(155) MeV (first neutron)
S_P = 21.123(174) MeV (first proton)Half-life:18.8(2) msDecay constant λ:36.869530880848 s^-1Specific activity α:7.929768157294 × 10⁺²³ Bq g^-1
21431805830526 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:2.9642(134) femtometer fmYear of discovery:1979

Radioactive Decay

Half-life T_½ = 18.8(2) ms respectively 1.88 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	²⁸Na	84.3(11) %	12.29(13) MeV
β^-, n	²⁷Na	12(1) %	8.75(13) MeV
β^-, 2n	²⁶Na	3.7(5) %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 18) and isobaric (same nucleon number A = 28) with Neon-28. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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

External data and identifiers

Adopted Levels, Gammas:NuDat 28Ne

Literature and References

[1] - T. J. M. Symons, Y. P. Viyogi, G. D. Westfall et al.:
Observation of New Neutron-Rich Isotopes by Fragmentation of 205-MeV/Nucleon ⁴⁰Ar Ions.
In: Physical Review Letters, 42, 40, (1979), DOI 10.1103/PhysRevLett.42.40.