Isotopes of phosphorus

Main isotopes of phosphorus (15P)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
31P 100% stable
32P trace 14.28 d β− 32S
33P trace 25.3 d β− 33S
Standard atomic weight (Ar, standard)
  • 30.973761998(5)[1]

Although phosphorus (15P) has 24 isotopes from 24P to 47P. Only one of these isotopes, 31P, is stable; as such, phosphorus is considered a monoisotopic element. The longest-lived radioactive isotopes are 33P with a half-life of 25.34 days and 32P with a half-life of 14.263 days. All others have lived under 2.5 minutes, most under a second. The least stable is 25P with a half-life shorter than 30 nanoseconds—the half-life of 24P is unknown.

Radioactive isotopes

Phosphorus-32

32P, a beta-emitter (1.71 MeV) with a half-life of 14.3 days, is used routinely in life-science laboratories, primarily to produce radiolabeled DNA and RNA probe, e.g. for use in Northern blots or Southern blots. Because the high-energy beta particles produced penetrate skin and corneas, and because any 32P ingested, inhaled, or absorbed is readily incorporated into bone and nucleic acids, OSHA requires that a lab coat, disposable gloves, and safety glasses or goggles be worn when working with 32P, and that working directly over an open container be avoided in order to protect the eyes. Monitoring personal, clothing, and surface contamination is also required. In addition, due to the high energy of the beta particles, shielding this radiation with the normally used dense materials (e.g. lead), gives rise to secondary emission of X-rays via a process known as bremsstrahlung, meaning braking radiation. Therefore, shielding must be accomplished with low-density materials, e.g. Plexiglas, Lucite, plastic, wood, or water.

Phosphorus-33

33P, a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as DNA sequencing. Phosphorus-33 can be used to label nucleotides. It is less energetic than 32P, giving a better resolution. A disadvantage is its higher cost compared to 32P, as most of the bombarded 31P will have acquired only one neutron, while only some will have acquired two or more. Its maximum specific activity is 5118 Ci/mol.

List of isotopes

nuclide
symbol		 Z(p) N(n)  
isotopic mass (u)
 		 half-life decay
mode(s)[2]		 daughter
isotope(s)[n 1]		 nuclear
spin and
parity		 representative
isotopic
composition
(mole fraction)		 range of natural
variation
(mole fraction)
24P 15 9 24.03435(54)# ? p (>99.9%) 23Si (1+)#
β+ (<.1%) 24Si
25P 15 10 25.02026(21)# <30 ns p 24Si (1/2+)#
26P[n 2] 15 11 26.01178(21)# 43.7(6) ms β+ (98.1%) 26Si (3+)
β+, 2p (1.0%) 24Mg
β+, p (.9%) 25Al
27P 15 12 26.999230(28) 260(80) ms β+ (99.93%) 27Si 1/2+
β+, p (.07%) 26Al
28P 15 13 27.992315(4) 270.3(5) ms β+ (99.99%) 28Si 3+
β+, p (.0013%) 27Al
β+, α (8.6×10−4%) 24Mg
29P 15 14 28.9818006(6) 4.142(15) s β+ 29Si 1/2+
30P 15 15 29.9783138(3) 2.498(4) min β+ 30Si 1+
31P 15 16 30.97376163(20) Stable 1/2+ 1.0000
32P 15 17 31.97390727(20) 14.263(3) d β− 32S 1+ trace
33P 15 18 32.9717255(12) 25.34(12) d β− 33S 1/2+
34P 15 19 33.973636(5) 12.43(8) s β− 34S 1+
35P 15 20 34.9733141(20) 47.3(7) s β− 35S 1/2+
36P 15 21 35.978260(14) 5.6(3) s β− 36S 4−#
37P 15 22 36.97961(4) 2.31(13) s β− 37S 1/2+#
38P 15 23 37.98416(11) 0.64(14) s β− (88%) 38S
β−, n (12%) 37S
39P 15 24 38.98618(11) 190(50) ms β− (74%) 39S 1/2+#
β−, n (26%) 38S
40P 15 25 39.99130(15) 153(8) ms β− (70%) 40S (2−,3−)
β−, n (30%) 39S
41P 15 26 40.99434(23) 100(5) ms β− (70%) 41S 1/2+#
β−, n (30%) 40S
42P 15 27 42.00101(48) 48.5(15) ms β− (50%) 42S
β−, n (50%) 41S
43P 15 28 43.00619(104) 36.5(15) ms β−, n 42S 1/2+#
44P 15 29 44.01299(75)# 18.5(25) ms β− 44S
45P 15 30 45.01922(86)# 8# ms [>200 ns] β− 45S 1/2+#
46P 15 31 46.02738(97)# 4# ms [>200 ns] β− 46S
  1. ↑ Bold for stable isotopes
  2. ↑ Has 1 halo proton

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.

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. Archived from the original (PDF) on 2008-09-23.
  • 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. Archived from the original (PDF) on 2008-09-23.
    • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005. Check date values in: |accessdate= (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.
  1. ↑ Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. ↑ "Universal Nuclide Chart". nucleonica. (Registration required (help)).
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