Isotopes of phosphorus

Jump to navigation Jump to search

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

External links

Template:Isotope nav Template:WikiDoc Sources