Oxygen-26

Properties and data of the isotope ²⁶O.

Contents

Oxygen-26 is a radioisotope of the chemical element oxygen, which has 18 neutrons in its atomic nucleus in addition to the element-specific 8 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 26. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁶O is exclusively for academic purposes.

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

General data

Name of the isotope:Oxygen-26; O-26Symbol:²⁶O or 268OMass number A:26 (= number of nucleons)Atomic number Z:8 (= number of protons)Neutrons N:18Isotopic mass:26.03721(18) u (atomic weight of Oxygen-26)Nuclide mass:26.0328214 u (calculated nuclear mass without electrons)Mass excess:34.66089 MeVMass defect:0.181358744 u (per nucleus)Nuclear binding energy:168.93458188 MeV (per nucleus)
6.49748392 MeV (average binding energy per nucleon)Separation energy:S_N = 0.739(10) MeV (first neutron)
S_P = 28.61(53) MeV (first proton)Half-life:4.2(33) psDecay constant λ:165035042990.46 s^-1Specific activity α:3.822554906593 × 10⁺³³ Bq g^-1
1.033122947727 × 10⁺²³ Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:2012

Radioactive Decay

Half-life T_½ = 4.2(33) ps respectively 4.2 × 10^-12 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
2n	²⁴O	100 %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 18) and isobaric (same nucleon number A = 26) with Oxygen-26. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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