Isotopes of phosphorus

Isotopes of phosphorus (15P)
Main isotopes Decay
Isotope abun­dance half-life (t1/2) mode pro­duct
31P 100% stable
32P trace 14.269 d β− 32S
33P trace 25.35 d β− 33S
Standard atomic weight Ar°(P)
  • 30.973761998±0.000000005
  • 30.974±0.001 (abridged)
Phosphorus has many allotropes, including white phosphorus (left), red phosphorus (center left, center right), and violet phosphorus (right). See allotropes of phosphorus for more information.

Although phosphorus (15P) has 22 known isotopes from 26P to 47P, only 31P is stable; Phosphorus is thus considered a monoisotopic element. 31P is also the only naturally occurring isotopes of phosphorus, so phosphorus is considered a mononuclidic element as well. The longest-lived radioactive isotopes are 33P with a half-life of 25.35 days and 32P with a half-life of 14.269 days. All others have half-lives of under 2.5 minutes, most under a second.

List of isotopes


Nuclide
 Z N Isotopic mass (Da)
 Discovery
year		 Half-life
 Decay
mode
 Daughter
isotope
 Spin and
parity
 Isotopic
abundance
Excitation energy
26P 15 11 26.011806(11) 1983 43.6(3) ms β+ (62.9%) 26Si (3)+
β+, p (35.1%) 25Al
β+, 2p (1.99%) 24Mg
26mP 164.4(1) keV 2017 115(8) ns IT 26P (1+)
27P 15 12 26.9992925(97) 1977 260(80) ms β+ (99.93%) 27Si 1/2+
β+, p (0.07%) 26Al
28P 15 13 27.9923265(12) 1953 270.3(5) ms β+ 28Si 3+
β+, p (.0013%) 27Al
β+, α (8.6×10−4%) 24Mg
29P 15 14 28.98180037(39) 1941 4.102(4) s β+ 29Si 1/2+
30P 15 15 29.978313490(69) 1934 2.5000(17) min β+ 30Si 1+
31P 15 16 30.97376199768(80) 1920 Stable 1/2+ 1.0000
32P 15 17 31.973907643(42) 1934 14.269(7) d β− 32S 1+ Trace
33P 15 18 32.9717257(12) 1951 25.35(11) d β− 33S 1/2+
34P 15 19 33.97364589(87) 1945 12.43(10) s β− 34S 1+
35P 15 20 34.9733140(20) 1971 47.3(8) s β− 35S 1/2+
36P 15 21 35.978260(14) 1971 5.6(3) s β− 36S 4−
β−, n? 35S
37P 15 22 36.979607(41) 1971 2.31(13) s β− 37S (1/2+)
β−, n? 36S
38P 15 23 37.984303(78) 1971 0.64(14) s β− (88%) 38S (2−)
β−, n (12%) 37S
39P 15 24 38.98629(12) 1977 282(24) ms β− (74%) 39S (1/2+)
β−, n (26%) 38S
40P 15 25 39.991262(90) 1979 150(8) ms β− (84.2%) 40S (2−,3−)
β−, n (15.8%) 39S
β−, 2n? 38S
41P 15 26 40.99465(13) 1979 101(5) ms β− (70%) 41S 1/2+#
β−, n (30%) 40S
β−, 2n? 39S
42P 15 27 42.00117(10) 1979 48.5(15) ms β− (50%) 42S
β−, n (50%) 41S
β−, 2n? 40S
43P 15 28 43.00541(32)# 1989 35.8(13) ms β−, n 42S (1/2+)
β−, 2n ? 41S
44P 15 29 44.01193(43)# 1989 18.5(25) ms β−, n (55%) 43S
β− (24%) 44S
β−, 2n (21%) 42S
45P 15 30 45.01713(54)# 1990 24(7 (stat), 9 (sys)) ms β−, n (79%) 44S 1/2+#
β−, 2n (21%) 43S
46P 15 31 46.02452(54)# 1990 9# ms
[>200 ns]		 β−? 46S
β−, n? 45S
β−, 2n? 44S
47P 15 32 47.03093(64)# 2018 4# ms
[>400 ns]		 β− 47S 1/2+#
β−, n? 46S
β−, 2n? 45S
This table header & footer:
  1. ↑ mP – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ↑ Modes of decay:
    IT:Isomeric transition
    n:Neutron emission
    p:Proton emission
  6. ↑ Bold symbol as daughter – Daughter product is stable.
  7. ↑ ( ) spin value – Indicates spin with weak assignment arguments.

Radioactive isotopes

Phosphorus-32

32P is a radioactive isotope of phosphorus with relative atomic mass 31.973907 Da and half-life of 14.26 days. 32P is a radioactive isotope of phosphorus with beta particle-emitting radiocytotoxic activity. Emitted by 32P, beta particles directly damage cellular DNA and, by ionizing intracellular water to produce several types of cytotoxic free radicals and superoxides, indirectly damage intracellular biological macromolecules, resulting in tumor cell death.

Phosphorus-33

Phosphorus-33 is a radioactive isotope of phosphorus; it is produced from sulfur-33. is a pure β-emitter, like 32P, and can be used as an alternative to it in research in molecular biology. Indeed, its longer half-life and especially its lower decay energy make its manipulation simpler in the laboratory. In the medical field, 33P has been used in the treatment of arterial stenosis but is no longer indicated at this time.

See also

Daughter products other than phosphorus

References

  1. 1 2 3 4 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3) 030001. doi:10.1088/1674-1137/abddae.
  2. ↑ "Standard Atomic Weights: Phosphorus". CIAAW. 2013.
  3. ↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ↑ 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.
  5. ↑ FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isotope Database". doi:10.11578/frib/2279152.
  6. ↑ FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isomer Database". doi:10.11578/frib/2572219.
  7. ↑ Chen, Z. Y.; Yan, X. L.; Hou, S. Q.; Liu, J. B.; Shi, J. Y.; Zhou, X. H.; Zhang, Y. H.; Wang, M.; Zhou, X.; Zhang, M.; Li, H. F.; Sun, M. Z.; Xing, Y. M.; Shuai, P.; Xu, X.; Huang, W. J.; Wang, Q.; Song, Y. N.; Deng, H. Y.; Jiao, H. Y.; Luo, Y. F.; Litvinov, Yu. A.; Blaum, K.; Yamaguchi, T. (1 December 2025). "Precision Mass Measurement of 26 P and 27 S and Their Impact on the 26 P( p , γ ) 27 S Reaction in Stellar X-Ray Bursts". The Astrophysical Journal. 994 (2): 270. doi:10.3847/1538-4357/ae1470.
  8. 1 2 Crawford, H. L.; Tripathi, V.; Allmond, J. M.; et al. (2022). "Crossing N = 28 toward the neutron drip line: first measurement of half-lives at FRIB". Physical Review Letters. 129 (212501) 212501. Bibcode:2022PhRvL.129u2501C. doi:10.1103/PhysRevLett.129.212501. OSTI 1898972. PMID 36461950. S2CID 253600995.
  9. ↑ "Phosphorus-32".
  10. ↑ Lewis, R.E. (January 1967). "PREPARATION OF PHOSPHORUS-33 BY IRRADIATION OF ENRICHED SULFUR-33 IN HIGHLY THERMALIZED FLUX". Oak Ridge National Laboratory.
  11. ↑ "Phosphorus 33 (P-33)". www.biotrend.com. Archived from the original on 2024-11-29. Retrieved 2025-12-26.