Oxygen-17

Oxygen-17

Diagram of an oxygen-17 atom
General
Symbol	17O
Names	oxygen-17
Protons (Z)	8
Neutrons (N)	9
Nuclide data
Natural abundance	0.0379% (SMOW) [1]
Half-life (t1/2)	stable
Isotope mass	16.999131756 [2] Da
Spin	+5/2
Excess energy	−809 keV
Binding energy	131763 keV
Isotopes of oxygen Complete table of nuclides

Oxygen-17 (¹⁷O) is a stable isotope of oxygen with a low isotopic abundance of about 0.038% (still more than twice as high as deuterium).

As the only stable isotope of oxygen possessing a nuclear spin (+5⁄2) and a favorable characteristic of field-independent relaxation in liquid water, ¹⁷O enables NMR studies of oxidative metabolic pathways through compounds containing ¹⁷O (i.e. metabolically produced H₂¹⁷O water by oxidative phosphorylation in mitochondria ^[3] ) at high magnetic fields.

Water used as nuclear reactor coolant is subjected to intense neutron flux. Natural water starts out with 0.038% of ¹⁷O; heavy water starts out incidentally enriched to about 0.055% in that isotopes. Further, the neutron flux slowly converts ¹⁶O in the cooling water to ¹⁷O by neutron capture, increasing its concentration. The neutron flux slowly converts ¹⁷O (with much greater cross section) in the cooling water to carbon-14, an undesirable product that can escape to the environment:

¹⁷O (n,α) → ¹⁴C

Some tritium removal facilities make a point of replacing the oxygen of the water with natural oxygen (mostly ¹⁶O) to give the added benefit of reducing ¹⁴C production. ^{[4] [5]}

History

The isotope was first hypothesized and subsequently imaged by Patrick Blackett in Rutherford's lab in 1925: ^[6]

Of the nature of the integrated nucleus little can be said without further data. It must however have a mass 17, and provided no other nuclear electrons are gained or lost in the process, an atomic number 8. It ought therefore to be an isotope of oxygen. If it is stable it should exist on the earth.

—  Patrick Blackett

It was a product out of the first man-made transmutation of ¹⁴N and ⁴He²⁺ conducted by Frederick Soddy and Ernest Rutherford in 1917–1919. ^[7] Its presence in Earth's atmosphere was later detected in 1929 by Giauque and Johnson in absorption spectra, ^[8] demonstrating its natural existece.

References

1. "Reference Sheet for International Measurement Standards" (PDF). International Atomic Energy Agency. December 2006. Archived from the original (PDF) on 2020-07-29.
2. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3) 030003. doi:10.1088/1674-1137/abddaf.
3. Arai, T.; S. Nakao; K. Mori; K. Ishimori; I. Morishima; T. Miyazawa; B. Fritz-Zieroth (31 May 1990). "Cerebral Oxygen Utilization Analyzed by the Use of Oxygen-17 and its Nuclear Magnetic Resonance". Biochem. Biophys. Res. Commun. 169 (1): 153–158. doi:10.1016/0006-291X(90)91447-Z. PMID   2350339.
4. http://www.nrc.gov/docs/ML1016/ML101650129.pdf Estimation of Carbon-14 in Nuclear Power Plant Gaseous Effluents; EPRI; June 10, 2010
5. A Compact, Low Cost, Tritium Removal Plant for Candu-6 Reactors; S.K. Sood, C. Fong, and K.M. Kalyanam; Ontario Hydro
6. Blackett, P. M. S. (1925). "The Ejection of Protons from Nitrogen Nuclei, Photographed by the Wilson Method". Proceedings of the Royal Society of London. Series A. 107 (742): 349–360. Bibcode:1925RSPSA.107..349B. doi: 10.1098/rspa.1925.0029 .
7. Rutherford, Ernest (1919). "Collision of alpha particles with light atoms IV. An anomalous effect in nitrogen". Philosophical Magazine. 6th series. 37: 581–587. doi:10.1080/14786440608635919.
8. Giauque, W. F.; Johnston, H. L. (1929). "An Isotope of Oxygen, Mass 17, in the Earth's Atmosphere". J. Am. Chem. Soc. 51 (12): 3528–3534. doi:10.1021/ja01387a004.

Lighter: oxygen-16	Oxygen-17 is an isotope of oxygen	Heavier: oxygen-18
Decay product of: nitrogen-17, fluorine-17	Decay chain of oxygen-17	Decays to: stable