# Isotopen van protactinium

Het chemisch element protactinium (Pa), met een atoommassa van 231,03588(2) u, bezit geen stabiele isotopen en wordt dus geclassificeerd als radioactief element. De 28 radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een seconde).
In de natuur komen sporen van de radio-isotopen $^{234}$Pa en $^{234m}$Pa voor. De isotoop $^{231}$Pa, met een halfwaardetijd van meer dan 32.000 jaar, komt echter het meest voor: de natuurlijke abundantie bedraagt quasi 100%.
De kortstlevende isotoop van protactinium is $^{213}$Pa, met een halfwaardetijd van ongeveer 7 milliseconden. De langstlevende is $^{231}$Pa, met een halfwaardetijd van 32.760 jaar.

## Overzicht

| Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | VP | Kernspin | Isotopische verhouding (molfractie) |
| Natuurlijk voorkomen (molfractie) |||
| $^{212}$Pa | 91 | 121 | 212,02320(8) | 8(5) ms | | | 7$^+$ | |
| $^{213}$Pa | 91 | 122 | 213,02111(8) | 7(3) ms | α | $^{209}$Ac | 9/2$^−$ | |
| $^{214}$Pa | 91 | 123 | 214,02092(8) | 17(3) ms | α | $^{210}$Ac | | |
| $^{215}$Pa | 91 | 124 | 215,01919(9) | 14(2) ms | α | $^{211}$Ac | 9/2$^−$ | |
| $^{216}$Pa | 91 | 125 | 216,01911(8) | 105(12) ms | α (80%) | $^{212}$Ac | | |
| $^{216}$Pa | 91 | 125 | 216,01911(8) | 105(12) ms | β$^+$ (20%) | $^{216}$Th | | |
| $^{217}$Pa | 91 | 126 | 217,01832(6) | 3,48(9) ms | α | $^{213}$Ac | 9/2$^−$ | |
| $^{217m}$Pa | 1860(7) keV | 1860(7) keV | 1860(7) keV | 1,08(3) ms | α | $^{213}$Ac | 29/2$^+$ | |
| $^{217m}$Pa | 1860(7) keV | 1860(7) keV | 1860(7) keV | 1,08(3) ms | IT (zelden) | $^{217}$Pa | 29/2$^+$ | |
| $^{218}$Pa | 91 | 127 | 218,020042(26) | 0,113(1) ms | α | $^{214}$Ac | | |
| $^{219}$Pa | 91 | 128 | 219,01988(6) | 53(10) ns | α | $^{215}$Ac | 9/2$^−$ | |
| $^{219}$Pa | 91 | 128 | 219,01988(6) | 53(10) ns | β$^+$ (5 × 10$^{−9}$%) | $^{219}$Th | 9/2$^−$ | |
| $^{220}$Pa | 91 | 129 | 220,02188(6) | 780(160) ns | α | $^{216}$Ac | 1$^−$ | |
| $^{221}$Pa | 91 | 130 | 221,02188(6) | 4,9(8) µs | α | $^{217}$Ac | 9/2$^−$ | |
| $^{222}$Pa | 91 | 131 | 222,02374(8) | 3,2(3) ms | α | $^{218}$Ac | | |
| $^{223}$Pa | 91 | 132 | 223,02396(8) | 5,1(6) ms | α | $^{219}$Ac | | |
| $^{223}$Pa | 91 | 132 | 223,02396(8) | 5,1(6) ms | β$^+$ (0,001%) | $^{223}$Th | | |
| $^{224}$Pa | 91 | 133 | 224,025626(17) | 844(19) ms | α (99,9%) | $^{220}$Ac | 5$^−$ | |
| $^{224}$Pa | 91 | 133 | 224,025626(17) | 844(19) ms | β$^+$ (0,1%) | $^{224}$Th | 5$^−$ | |
| $^{225}$Pa | 91 | 134 | 225,02613(8) | 1,7(2) s | α | $^{221}$Ac | 5/2$^−$ | |
| $^{226}$Pa | 91 | 135 | 226,027948(12) | 1,8(2) min | α (74%) | $^{222}$Ac | | |
| $^{226}$Pa | 91 | 135 | 226,027948(12) | 1,8(2) min | β$^+$ (26%) | $^{226}$Th | | |
| $^{227}$Pa | 91 | 136 | 227,028805(8) | 38,3(3) min | α (85%) | $^{223}$Ac | (5/2$^−$) | |
| $^{227}$Pa | 91 | 136 | 227,028805(8) | 38,3(3) min | EV (15%) | $^{227}$Th | (5/2$^−$) | |
| $^{228}$Pa | 91 | 137 | 228,031051(5) | 22(1) uur | β$^+$ (98,15%) | $^{228}$Th | 3$^+$ | |
| $^{228}$Pa | 91 | 137 | 228,031051(5) | 22(1) uur | α (1,85%) | $^{224}$Ac | 3$^+$ | |
| $^{229}$Pa | 91 | 138 | 229,0320968(30) | 1,50(5) dagen | EV (99,52%) | $^{229}$Th | (5/2$^+$) | |
| $^{229}$Pa | 91 | 138 | 229,0320968(30) | 1,50(5) dagen | α (0,48%) | $^{225}$Ac | (5/2$^+$) | |
| $^{229m}$Pa | 11,6(3) keV | 11,6(3) keV | 11,6(3) keV | 420(30) ns | | | 3/2$^−$ | |
| $^{230}$Pa | 91 | 139 | 230,034541(4) | 17,4(5) dagen | β$^+$ (91,6%) | $^{230}$Th | (2$^−$) | |
| $^{230}$Pa | 91 | 139 | 230,034541(4) | 17,4(5) dagen | β$^−$ (8,4%) | $^{230}$U | (2$^−$) | |
| $^{230}$Pa | 91 | 139 | 230,034541(4) | 17,4(5) dagen | α (0,00319%) | $^{226}$Ac | (2$^−$) | |
| $^{231}$Pa | 91 | 140 | 231,0358840(24) | 3,276(11) × 10$^4$ jaar | α | $^{227}$Ac | 3/2$^−$ | 1,0000 |
| $^{231}$Pa | 91 | 140 | 231,0358840(24) | 3,276(11) × 10$^4$ jaar | CV (1,34 × 10$^{−9}$%) | $^{207}$Tl, $^{24}$Ne | 3/2$^−$ | 1,0000 |
| $^{231}$Pa | 91 | 140 | 231,0358840(24) | 3,276(11) × 10$^4$ jaar | SS (3 × 10$^{−10}$%) | | 3/2$^−$ | 1,0000 |
| $^{231}$Pa | 91 | 140 | 231,0358840(24) | 3,276(11) × 10$^4$ jaar | CV (10$^{−12}$%) | $^{208}$Pb, $^{23}$F | 3/2$^−$ | 1,0000 |
| $^{232}$Pa | 91 | 141 | 232,038592(8) | 1,31(2) dagen | β$^−$ | $^{232}$U | (2$^−$) | |
| $^{232}$Pa | 91 | 141 | 232,038592(8) | 1,31(2) dagen | EV (0,003%) | $^{232}$Th | (2$^−$) | |
| $^{233}$Pa | 91 | 142 | 233,0402473(23) | 26,975(13) dagen | β$^−$ | $^{233}$U | 3/2$^−$ | |
| $^{234}$Pa | 91 | 143 | 234,043308(5) | 6,70(5) uur | β$^−$ | $^{234}$U | 4$^+$ | sporen |
| $^{234}$Pa | 91 | 143 | 234,043308(5) | 6,70(5) uur | SS (3 × 10$^{−10}$%) | | 4$^+$ | sporen |
| $^{234m}$Pa | 78(3) keV | 78(3) keV | 78(3) keV | 1,17(3) min | β$^−$ (99,83%) | $^{234}$U | (0$^−$) | sporen |
| $^{234m}$Pa | 78(3) keV | 78(3) keV | 78(3) keV | 1,17(3) min | IT (0,16%) | $^{234}$Pa | (0$^−$) | sporen |
| $^{234m}$Pa | 78(3) keV | 78(3) keV | 78(3) keV | 1,17(3) min | SS (10$^{−10}$%) | | (0$^−$) | sporen |
| $^{235}$Pa | 91 | 144 | 235,04544(5) | 24,44(11) min | β$^−$ | $^{235m}$U | (3/2$^−$) | |
| $^{236}$Pa | 91 | 145 | 236,04868(21) | 9,1(1) min | β$^−$ | $^{236}$U | 1$^−$ | |
| $^{236}$Pa | 91 | 145 | 236,04868(21) | 9,1(1) min | β$^−$, SS (6 × 10$^{−8}$%) | | 1$^−$ | |
| $^{237}$Pa | 91 | 146 | 237,05115(11) | 8,7(2) min | β$^−$ | $^{237}$U | (1/2$^+$) | |
| $^{238}$Pa | 91 | 147 | 238,05450(6) | 2,27(9) min | β$^−$ | $^{238}$U | (3$^−$) | |
| $^{238}$Pa | 91 | 147 | 238,05450(6) | 2,27(9) min | β$^−$, SS (2,6 × 10$^{−6}$%) | | (3$^−$) | |
| $^{239}$Pa | 91 | 148 | 239,05726(21) | 1,8(5) uur | β$^−$ | $^{239}$U | (3/2$^−$) | |
| $^{240}$Pa | 91 | 149 | 240,06098(32) | 2 min | β$^−$ | $^{240}$U | | |

## Overzicht van isotopen per element

* (en) R.B. Firestone, S.Y. Frank Chu & C.M. Baglin (1999) - Table of Isotopes (online versie van de cd-rom)
* (en) G. Audi, A.H. Wapstra, C. Thibault, J. Blachot & O. Bersillon (2003) - The NUBASE evaluation of nuclear and decay properties, Nuclear Physics A, 729, pp. 3-128
* (en) J.R. de Laeter, J.K. Böhlke, P. De Bièvre, H. Hidaka, H.S. Peiser, K.J.R. Rosman & P.D.P. Taylor (2003) - Atomic weights of the elements. Review 2000 (IUPAC Technical Report), Pure and Applied Chemistry, 75 (6), pp. 683–800
* (en) M.E. Wieser (2006) - Atomic weights of the elements 2005 (IUPAC Technical Report), Pure and Applied Chemistry, 78 (11), pp. 2051–2066
* (en) David R. Lide (2004) - CRC Handbook of Chemistry and Physics (85th ed.), hoofdstuk 11, CRC Press - ISBN 978-0849304859
$^{211}$Pa · $^{212}$Pa · $^{213}$Pa · $^{214}$Pa · $^{215}$Pa · $^{216}$Pa · $^{217}$Pa · $^{217m}$Pa · $^{218}$Pa · $^{219}$Pa · $^{220}$Pa · $^{221}$Pa · $^{222}$Pa · $^{223}$Pa · $^{224}$Pa · $^{225}$Pa · $^{226}$Pa · $^{227}$Pa · $^{228}$Pa · $^{229}$Pa · $^{229m}$Pa · $^{230}$Pa · $^{231}$Pa · $^{232}$Pa · $^{233}$Pa · $^{234}$Pa · $^{234m}$Pa · $^{235}$Pa · $^{236}$Pa · $^{237}$Pa · $^{238}$Pa · $^{239}$Pa · $^{240}$Pa · $^{241}$Pa