Isotopes of phosphorus
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Although phosphorus (P) has multiple isotopes, only one of these isotopes is stable 31P; as such, it is considered a monoisotopic element.
Standard atomic mass: 30.973762(2) u
Radioactive isotopes of phosphorus include:
- 32P; a beta-emitter (1.71 MeV) with a half-life of 14.3 days which is used routinely in life-science laboratories, primarily to produce radiolabeled DNA and RNA probes, 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.[1]
- 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.
Table
| nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life | nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|
| excitation energy | |||||||
| 24P | 15 | 9 | 24.03435(54)# | (1+)# | |||
| 25P | 15 | 10 | 25.02026(21)# | <30 ns | (1/2+)# | ||
| 26P | 15 | 11 | 26.01178(21)# | 43.7(6) ms | (3+) | ||
| 27P | 15 | 12 | 26.999230(28) | 260(80) ms | 1/2+ | ||
| 28P | 15 | 13 | 27.992315(4) | 270.3(5) ms | 3+ | ||
| 29P | 15 | 14 | 28.9818006(6) | 4.142(15) s | 1/2+ | ||
| 30P | 15 | 15 | 29.9783138(3) | 2.498(4) min | 1+ | ||
| 31P | 15 | 16 | 30.97376163(20) | STABLE | 1/2+ | 1.0000 | |
| 32P | 15 | 17 | 31.97390727(20) | 14.263(3) d | 1+ | ||
| 33P | 15 | 18 | 32.9717255(12) | 25.34(12) d | 1/2+ | ||
| 34P | 15 | 19 | 33.973636(5) | 12.43(8) s | 1+ | ||
| 35P | 15 | 20 | 34.9733141(20) | 47.3(7) s | 1/2+ | ||
| 36P | 15 | 21 | 35.978260(14) | 5.6(3) s | 4-# | ||
| 37P | 15 | 22 | 36.97961(4) | 2.31(13) s | 1/2+# | ||
| 38P | 15 | 23 | 37.98416(11) | 0.64(14) s | |||
| 39P | 15 | 24 | 38.98618(11) | 190(50) ms | 1/2+# | ||
| 40P | 15 | 25 | 39.99130(15) | 153(8) ms | (2-,3-) | ||
| 41P | 15 | 26 | 40.99434(23) | 100(5) ms | 1/2+# | ||
| 42P | 15 | 27 | 42.00101(48) | 48.5(15) ms | |||
| 43P | 15 | 28 | 43.00619(104) | 36.5(15) ms | 1/2+# | ||
| 44P | 15 | 29 | 44.01299(75)# | 18.5(25) ms | |||
| 45P | 15 | 30 | 45.01922(86)# | 8# ms [>200 ns] | 1/2+# | ||
| 46P | 15 | 31 | 46.02738(97)# | 4# ms [>200 ns] | |||
Notes
- Values marked # are 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 first digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from FUKIC which use expanded uncertainties.
References
- Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
- Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
- Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.