Isotopes of protactinium

From Wikipedia, the free encyclopedia

Protactinium (Pa)
Standard atomic mass: 231.03588(2) u
The element has no stable isotopes. However, it has a characteristic terrestrial isotopic composition and thus an atomic mass can be given.

Isotopes of protactinium occurring within the radioactive disintegration chain of uranium were known as:

  • uranium X2 : 234mPa
  • uranium Z : 234Pa

[edit] 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
212Pa 91 121 212.02320(8) 8(5) ms [5.1(+61-19) ms] 7+#
213Pa 91 122 213.02111(8) 7(3) ms [5.3(+40-16) ms] 9/2-#
214Pa 91 123 214.02092(8) 17(3) ms
215Pa 91 124 215.01919(9) 14(2) ms 9/2-#
216Pa 91 125 216.01911(8) 105(12) ms
217Pa 91 126 217.01832(6) 3.48(9) ms 9/2-#
217mPa 1860(7) keV 1.08(3) ms 29/2+#
218Pa 91 127 218.020042(26) 0.113(1) ms
219Pa 91 128 219.01988(6) 53(10) ns 9/2-
220Pa 91 129 220.02188(6) 780(160) ns 1-#
221Pa 91 130 221.02188(6) 4.9(8) µs 9/2-
222Pa 91 131 222.02374(8)# 3.2(3) ms
223Pa 91 132 223.02396(8) 5.1(6) ms
224Pa 91 133 224.025626(17) 844(19) ms 5-#
225Pa 91 134 225.02613(8) 1.7(2) s 5/2-#
226Pa 91 135 226.027948(12) 1.8(2) min
227Pa 91 136 227.028805(8) 38.3(3) min (5/2-)
228Pa 91 137 228.031051(5) 22(1) h 3+
229Pa 91 138 229.0320968(30) 1.50(5) d (5/2+)
229mPa 11.6(3) keV 420(30) ns 3/2-
230Pa 91 139 230.034541(4) 17.4(5) d (2-)
231Pa 91 140 231.0358840(24) 3.276(11)E+4 a 3/2- 1.0000
232Pa 91 141 232.038592(8) 1.31(2) d (2-)
233Pa 91 142 233.0402473(23) 26.975(13) d 3/2-
234Pa 91 143 234.043308(5) 6.70(5) h 4+
234mPa 78(3) keV 1.17(3) min (0-)
235Pa 91 144 235.04544(5) 24.44(11) min (3/2-)
236Pa 91 145 236.04868(21) 9.1(1) min 1(-)
237Pa 91 146 237.05115(11) 8.7(2) min (1/2+)
238Pa 91 147 238.05450(6) 2.27(9) min (3-)#
239Pa 91 148 239.05726(21)# 1.8(5) h (3/2)(-#)
240Pa 91 149 240.06098(32)# 2# min

[edit] 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.

[edit] References


Isotopes of thorium Isotopes of protactinium Isotopes of uranium
Index to isotope pages