Isotopes of phosphorus

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.
• 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 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 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.

External links

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