Isotopes of sodium

There are twenty recognized isotopes of sodium, ranging from 18
Na to 37
Na and two isomers (22m
Na and 24m
Na). 23
Na is the only stable (and the only primordial) isotope. As such, it is considered a monoisotopic element and it has a relative atomic mass: 22.98976928(2). Sodium has two radioactive cosmogenic isotopes (22
Na, half-life = 2.605 years; and 24
Na, half-life ≈ 15 hours). With the exception of those two, all other isotopes have half-lives under a minute, most under a second. The shortest-lived is 18
Na, with a half-life of 6979129999999999999♠1.3(4)×10⁻²¹ seconds.

Acute neutron radiation exposure (e.g., from a nuclear criticality accident) converts some of the stable 23
Na in human blood plasma to 24
Na. By measuring the concentration of this isotope, the neutron radiation dosage to the victim can be computed.

22
Na is a positron-emitting isotope with a remarkably long half-life. It is used to create test-objects and point-sources for positron emission tomography.

Table

1. ↑ Abbreviations:
   IT: Isomeric transition
2. ↑ Bold for stable isotopes
3. 1 2 Cosmogenic nuclide

Notes

• Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
• Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.

Sodium-24

Sodium-24 is one of the most important isotopes. It is radioactive and created from common sodium-23 by neutron bombardment. With a 15-hour half life, 24
Na decays to 24
Mg by emission of an electron and two gamma rays. Exposure of the human body to intense neutron flux creates 24
Na in blood plasma. Measurements of its quantity are used to determine the absorbed radiation dose of the patient. This is used to determine the level of medical treatment required.

When the sodium-potassium alloy is used as a coolant in nuclear reactors, 24
Na is created, which makes the coolant radioactive. When the 24
Na decays, it causes a buildup of magnesium in the coolant. Since the half life is short, the 24
Na portion of the coolant ceases to be radioactive within a few days after removal from the reactor.

Sodium-22

Sodium-22 is being investigated as an efficient generator of “cold positrons” (essentially antimatter) to produce muons for catalyzing fusion of deuterium. The energy released would induce phenomenal specific impulse in a rocket engine, enabling probe missions to reach any outer planet in a few weeks instead of years or Alpha Centauri in less than a decade.

References

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. 
• Isotopic compositions and standard atomic masses from:
  • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683. 
  • M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary. 
• Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. 
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.  Check date values in: |access-date= (help)
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9. 
• Sodium-22 as fusion initiator:
  • Brian Wang. "Positron Dynamics near term work to proving out antimatter catalyzed deuterium fusion propulsion with over 100,000 ISP". NextBig Future. Retrieved October 25, 2016. 

External links

• Sodium isotopes data from The Berkeley Laboratory Isotopes Project's

1. ↑ "Universal Nuclide Chart". nucleonica. (registration required (help)). 

Isotopes of the chemical elements
1 H																	2 He
3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
55 Cs	56 Ba		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
87 Fr	88 Ra		104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Nh	114 Fl	115 Mc	116 Lv	117 Ts	118 Og
		57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
		89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr
Table of nuclides Categories: Isotopes Tables of nuclides Metastable isotopes Isotopes by element