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Isotopes of protactinium
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<h2 id="list-of-isotopes">List of isotopes</h2> <table><tbody><tr><th rowspan="2">Nuclide<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a></th><th rowspan="2">Historicname</th><th rowspan="1"><a href="/facts/Atomic_number/bgAr581S"><i>Z</i></a></th><th rowspan="1"><a href="/facts/Neutron_number/eNtwGnVL"><i>N</i></a></th><th rowspan="1"><a href="/facts/Atomic_mass/J1FJY9MV">Isotopic mass</a> (<a href="/facts/Dalton_(unit)/IMATU3vf">Da</a>)<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a><a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a></th><th rowspan="2"><a href="/facts/Half-life/kGVH8BAB">Half-life</a><a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a><a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a></th><th rowspan="2"><a href="/facts/Decay_mode/Ya6FVjt4">Decaymode</a><a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a></th><th rowspan="2"><a href="/facts/Decay_product/hT0obfLv">Daughterisotope</a><a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a></th><th rowspan="2"><a href="/facts/Spin_(particle_physics)/4Jvp7e8P">Spin</a> and<a href="/facts/Parity_(physics)/emSbJ4hD">parity</a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a><a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a><a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a></th><th rowspan="2"><a href="/facts/Natural_abundance/dGjaAwc9">Isotopicabundance</a></th></tr><tr><th colspan="3">Excitation energy</th></tr><tr><td>210Pa<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a></td><td></td><td>91</td><td>119</td><td></td><td>6.0+1.5−1.1 ms</td><td><a href="/facts/Alpha_decay/rCsHNIUE">α</a></td><td>206Ac</td><td>3+</td><td></td></tr><tr><td>211Pa</td><td></td><td>91</td><td>120</td><td>211.023674(75)</td><td>6(3) ms</td><td>α</td><td>207Ac</td><td>9/2−</td><td></td></tr><tr><td>212Pa</td><td></td><td>91</td><td>121</td><td>212.023185(94)</td><td>5.8(19) ms</td><td>α</td><td>208Ac</td><td>3+#</td><td></td></tr><tr><td>213Pa</td><td></td><td>91</td><td>122</td><td>213.021100(61)</td><td>7.4(24) ms</td><td>α</td><td>209Ac</td><td>9/2−</td><td></td></tr><tr><td>214Pa</td><td></td><td>91</td><td>123</td><td>214.020891(87)</td><td>17(3) ms</td><td>α</td><td>210Ac</td><td>7+#</td><td></td></tr><tr><td>215Pa</td><td></td><td>91</td><td>124</td><td>215.019114(89)</td><td>14(2) ms</td><td>α</td><td>211Ac</td><td>9/2−</td><td></td></tr><tr><td>216Pa</td><td></td><td>91</td><td>125</td><td>216.019135(26)</td><td>105(12) ms</td><td>α</td><td>212Ac</td><td>5+#</td><td></td></tr><tr><td>217Pa</td><td></td><td>91</td><td>126</td><td>217.018309(13)</td><td>3.8(2) ms</td><td>α</td><td>213Ac</td><td>9/2−</td><td></td></tr><tr><td rowspan="2">217mPa</td><td rowspan="2"></td><td rowspan="2" colspan="3">1860(7) keV</td><td rowspan="2">1.08(3) ms</td><td>α (73%)</td><td>213Ac</td><td rowspan="2">(23/2−)</td><td rowspan="2"></td></tr><tr><td><a href="/facts/Isomeric_transition/L8DHcqnk">IT</a> (27%)</td><td>217Pa</td></tr><tr><td>218Pa</td><td></td><td>91</td><td>127</td><td>218.020021(19)</td><td>108(5) μs</td><td>α</td><td>214Ac</td><td>8−#</td><td></td></tr><tr><td>218mPa</td><td></td><td colspan="3">81(19) keV</td><td>150(50) μs</td><td>α</td><td>214Ac</td><td></td><td></td></tr><tr><td>219Pa</td><td></td><td>91</td><td>128</td><td>219.019950(75)</td><td>56(9) ns</td><td>α</td><td>215Ac</td><td>9/2−</td><td></td></tr><tr><td>220Pa</td><td></td><td>91</td><td>129</td><td>220.021770(16)</td><td>850(60) ns</td><td>α</td><td>216Ac</td><td>1−#</td><td></td></tr><tr><td>220m1Pa<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a></td><td></td><td colspan="3">26(23) keV</td><td>410(180) ns</td><td>α</td><td>216Ac</td><td></td><td></td></tr><tr><td>220m2Pa</td><td></td><td colspan="3">290(50) keV</td><td>260(210) ns</td><td>α</td><td>216Ac</td><td></td><td></td></tr><tr><td>221Pa</td><td></td><td>91</td><td>130</td><td>221.021873(64)</td><td>5.9(17) μs</td><td>α</td><td>217Ac</td><td>9/2−</td><td></td></tr><tr><td>222Pa</td><td></td><td>91</td><td>131</td><td>222.023687(93)</td><td>3.8(2) ms</td><td>α</td><td>218Ac</td><td>1−#</td><td></td></tr><tr><td>223Pa</td><td></td><td>91</td><td>132</td><td>223.023980(81)</td><td>5.3(3) ms</td><td>α</td><td>219Ac</td><td>9/2−</td><td></td></tr><tr><td>224Pa</td><td></td><td>91</td><td>133</td><td>224.0256173(81)</td><td>844(19) ms</td><td>α (99.9%)</td><td>220Ac</td><td>(5−)</td><td></td></tr><tr><td>225Pa</td><td></td><td>91</td><td>134</td><td>225.026148(88)</td><td>1.71(10) s</td><td>α</td><td>221Ac</td><td>5/2−#</td><td></td></tr><tr><td rowspan="2">226Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">135</td><td rowspan="2">226.027948(12)</td><td rowspan="2">1.8(2) min</td><td>α (74%)</td><td>222Ac</td><td rowspan="2">1−#</td><td rowspan="2"></td></tr><tr><td>β+ (26%)</td><td>226Th</td></tr><tr><td rowspan="2">227Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">136</td><td rowspan="2">227.0288036(78)</td><td rowspan="2">38.3(3) min</td><td>α (85%)</td><td>223Ac</td><td rowspan="2">(5/2−)</td><td rowspan="2"></td></tr><tr><td><a href="/facts/Electron_capture/EIccoV1u">EC</a> (15%)</td><td>227Th</td></tr><tr><td rowspan="2">228Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">137</td><td rowspan="2">228.0310508(47)</td><td rowspan="2">22(1) h</td><td>β+ (98.15%)</td><td>228Th</td><td rowspan="2">3+</td><td rowspan="2"></td></tr><tr><td>α (1.85%)</td><td>224Ac</td></tr><tr><td rowspan="2">229Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">138</td><td rowspan="2">229.0320956(35)</td><td rowspan="2">1.55(4) d</td><td>EC (99.51%)</td><td>229Th</td><td rowspan="2">5/2+</td><td rowspan="2"></td></tr><tr><td>α (0.49%)</td><td>225Ac</td></tr><tr><td>229mPa</td><td></td><td colspan="3">12.20(4) keV</td><td>420(30) ns</td><td>IT</td><td>229Pa</td><td>3/2−</td><td></td></tr><tr><td rowspan="3">230Pa</td><td rowspan="3"></td><td rowspan="3">91</td><td rowspan="3">139</td><td rowspan="3">230.0345397(33)</td><td rowspan="3">17.4(5) d</td><td>β+ (92.2%)</td><td>230Th</td><td rowspan="3">2−</td><td rowspan="3"></td></tr><tr><td>β− (7.8%)</td><td>230U</td></tr><tr><td>α (0.0032%)</td><td>226Ac</td></tr><tr><td rowspan="4">231Pa</td><td rowspan="4">Protoactinium</td><td rowspan="4">91</td><td rowspan="4">140</td><td rowspan="4">231.0358825(19)</td><td rowspan="4">3.265(20)×104 y</td><td>α</td><td>227Ac</td><td rowspan="4">3/2−</td><td rowspan="4">1.0000<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a></td></tr><tr><td><a href="/facts/Cluster_decay/sIelGo3t">CD</a> (1.34×10−10%)</td><td>207Tl24Ne</td></tr><tr><td><a href="/facts/Spontaneous_fission/0QuJoVKI">SF</a> (<3×10−10%)</td><td>(various)</td></tr><tr><td>CD (9.9×10−13%)</td><td><i>208Pb</i>23F</td></tr><tr><td>232Pa</td><td></td><td>91</td><td>141</td><td>232.0385902(82)</td><td>1.32(2) d</td><td>β−</td><td>232U</td><td>(2−)</td><td></td></tr><tr><td>233Pa</td><td></td><td>91</td><td>142</td><td>233.0402465(14)</td><td>26.975(13) d</td><td>β−</td><td>233U</td><td>3/2−</td><td>Trace<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a></td></tr><tr><td rowspan="2">234Pa</td><td rowspan="2">Uranium Z</td><td rowspan="2">91</td><td rowspan="2">143</td><td rowspan="2">234.0433056(44)</td><td rowspan="2">6.70(5) h</td><td>β−</td><td>234U</td><td rowspan="2">4+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a></td></tr><tr><td>SF (3×10−10%)</td><td>(various)</td></tr><tr><td rowspan="3">234mPa</td><td rowspan="3">Uranium X2Brevium</td><td rowspan="3" colspan="3">79(3) keV</td><td rowspan="3">1.159(11) min</td><td>β− (99.84%)</td><td>234U</td><td rowspan="3">(0−)</td><td rowspan="3">Trace<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a></td></tr><tr><td>IT (0.16%)</td><td>234Pa</td></tr><tr><td>SF (10−10%)</td><td>(various)</td></tr><tr><td>235Pa</td><td></td><td>91</td><td>144</td><td>235.045399(15)</td><td>24.4(2) min</td><td>β−</td><td><i>235U</i></td><td>3/2−</td><td></td></tr><tr><td rowspan="2">236Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">145</td><td rowspan="2">236.048668(15)</td><td rowspan="2">9.1(1) min</td><td>β−</td><td>236U</td><td rowspan="2">1(−)</td><td rowspan="2"></td></tr><tr><td>β−, SF (6×10−8%)</td><td>(various)</td></tr><tr><td>237Pa</td><td></td><td>91</td><td>146</td><td>237.051023(14)</td><td>8.7(2) min</td><td>β−</td><td>237U</td><td>1/2+</td><td></td></tr><tr><td rowspan="2">238Pa</td><td rowspan="2"></td><td rowspan="2">91</td><td rowspan="2">147</td><td rowspan="2">238.054637(17)</td><td rowspan="2">2.28(9) min</td><td>β−</td><td><i>238U</i></td><td rowspan="2">3−#</td><td rowspan="2"></td></tr><tr><td>β−, SF (2.6×10−6%)</td><td>(various)</td></tr><tr><td>239Pa</td><td></td><td>91</td><td>148</td><td>239.05726(21)#</td><td>1.8(5) h</td><td>β−</td><td>239U</td><td>1/2+#</td><td></td></tr><tr><th colspan="20"><i>This table header & footer:</i> <ul><li>view</li></ul></th></tr></tbody></table> <h2 id="actinides-and-fission-products">Actinides and fission products</h2> <h2 id="protactinium-230">Protactinium-230</h2> <p>Protactinium-230 has 139 <a href="/facts/Neutrons/oRCM1geb">neutrons</a> and a half-life of 17.4 days. Most of the time (92%), it undergoes beta plus decay to <a href="/facts/Thorium-230/lRb3opzg">230Th</a>, with a minor (8%) beta-minus decay branch leading to <a href="/facts/Uranium-230/zWIQ6MVL">230U</a>. It also has a very rare (.003%) alpha decay mode leading to <a href="/facts/Actinium-226/vnv59EsB">226Ac</a>.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> It is not found in nature because its half-life is short and it is not found in the <a href="/facts/Decay_chain/JvTwPNBn">decay chains</a> of 235U, 238U, or 232Th. It has a mass of 230.034541 u. </p><p>Protactinium-230 is of interest as a progenitor of uranium-230, an isotope that has been considered for use in <a href="/facts/Targeted_alpha-particle_therapy/steG07FI">targeted alpha-particle therapy</a> (TAT). It can be produced through proton or <a href="/facts/Deuteron/Bv4wfCkw">deuteron</a> irradiation of natural thorium.<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> </p> <h2 id="protactinium-231">Protactinium-231</h2> <p>Protactinium-231 is the longest-lived isotope of protactinium, with a half-life of 32,760 years. In nature, it is found in trace amounts as part of the <a href="/facts/Actinium_series/JvTwPNBn">actinium series</a>, which starts with the <a href="/facts/Primordial_isotope/lFAUqHDv">primordial isotope</a> <a href="/facts/Uranium-235/pe0RznDM">uranium-235</a>; the <a href="/facts/Secular_equilibrium/sshnQTf8">equilibrium</a> concentration in uranium ore is 46.55 231Pa per million 235U. In <a href="/facts/Nuclear_reactor/8xqjIbge">nuclear reactors</a>, it is one of the few long-lived radioactive <a href="/facts/Actinide/kHC4lxJV">actinides</a> produced as a byproduct of the projected <a href="/facts/Thorium_fuel_cycle/mohxxkx3">thorium fuel cycle</a>, as a result of (n,2n) reactions where a <a href="/facts/Fast_neutron/UMKR4XgJ">fast neutron</a> removes a <a href="/facts/Neutron/oRCM1geb">neutron</a> from <a href="/facts/Thorium-232/lRb3opzg">232Th</a> or <a href="/facts/Uranium-232/9sPn8oCm">232U</a>, and can also be destroyed by <a href="/facts/Neutron_capture/elsFpM12">neutron capture</a>, though the <a href="/facts/Neutron_cross_section/gAkJmXXA">cross section</a> for this reaction is also low. </p> <p>binding energy: 1759860 keV beta decay energy: −382 keV </p><p>spin: 3/2− mode of decay: <a href="/facts/Alpha_decay/rCsHNIUE">alpha</a> to 227Ac, also others </p><p>possible parent nuclides: <a href="/facts/Beta_decay/vxTBlckp">beta</a> from 231Th, <a href="/facts/Electron_capture/EIccoV1u">EC</a> from 231U, <a href="/facts/Alpha_decay/rCsHNIUE">alpha</a> from 235Np. </p> <h2 id="protactinium-233">Protactinium-233</h2> <p>Protactinium-233 is also part of the thorium fuel cycle. It is an intermediate beta decay product between <a href="/facts/Thorium-233/lRb3opzg">thorium-233</a> (produced from natural thorium-232 by neutron capture) and <a href="/facts/Uranium-233/a6sMrk07">uranium-233</a> (the fissile fuel of the thorium cycle). Some thorium-cycle reactor designs try to protect Pa-233 from further neutron capture producing Pa-234 and U-234, which are not useful as fuel. </p> <h2 id="protactinium-234">Protactinium-234</h2> <p>Protactinium-234 is a member of the <a href="/facts/Uranium_series/JvTwPNBn">uranium series</a> with a half-life of 6.70 hours. It was discovered by <a href="/facts/Otto_Hahn/7alx1Db7">Otto Hahn</a> in 1921.<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> </p> <h3>Protactinium-234m</h3> <p>Protactinium-234m is a member of the uranium series with a half-life of 1.17 minutes. It was discovered in 1913 by <a href="/facts/Kazimierz_Fajans/ubkxreh4">Kazimierz Fajans</a> and <a href="/facts/Oswald_Helmuth_G%25C3%25B6hring/pwCsTmfH">Oswald Helmuth Göhring</a>, who named it brevium for its short half-life.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> About 99.8% of decays of <a href="/facts/Thorium-234/lRb3opzg">234Th</a> produce this isomer instead of the <a href="/facts/Ground_state/ML7cfCug">ground state</a> (t1/2 = 6.70 hours).<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a> </p> <ul><li>Isotope masses from: <ul><li>Audi, Georges; Bersillon, Olivier; Blachot, Jean; <a href="/facts/Aaldert_Wapstra/9Ylvt18s">Wapstra, Aaldert Hendrik</a> (2003), <a href="https://hal.archives-ouvertes.fr/in2p3-00020241/document">"The NUBASE evaluation of nuclear and decay properties"</a>, <i>Nuclear Physics A</i>, 729: 3–128, <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2003NuPhA.729....3A">2003NuPhA.729....3A</a>, <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1016%2Fj.nuclphysa.2003.11.001">10.1016/j.nuclphysa.2003.11.001</a></li></ul></li> <li>Isotopic compositions and standard atomic masses from: <ul><li><a href="/facts/John_Robert_de_Laeter/jYQj55GI">de Laeter, John Robert</a>; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). <a href="https://doi.org/10.1351%2Fpac200375060683">"Atomic weights of the elements. Review 2000 (IUPAC Technical Report)"</a>. <i><a href="/facts/Pure_and_Applied_Chemistry/9QdCDKxf">Pure and Applied Chemistry</a></i>. 75 (6): 683–800. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1351%2Fpac200375060683">10.1351/pac200375060683</a>.</li> <li>Wieser, Michael E. (2006). <a href="https://doi.org/10.1351%2Fpac200678112051">"Atomic weights of the elements 2005 (IUPAC Technical Report)"</a>. <i><a href="/facts/Pure_and_Applied_Chemistry/9QdCDKxf">Pure and Applied Chemistry</a></i>. 78 (11): 2051–2066. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1351%2Fpac200678112051">10.1351/pac200678112051</a>.</li></ul></li> <li><a href="http://old.iupac.org/news/archives/2005/atomic-weights_revised05.html">"News & Notices: Standard Atomic Weights Revised"</a>. <i>International Union of Pure and Applied Chemistry</i>. 19 October 2005.</li> <li>Half-life, spin, and isomer data selected from the following sources. <ul><li>Audi, Georges; Bersillon, Olivier; Blachot, Jean; <a href="/facts/Aaldert_Wapstra/9Ylvt18s">Wapstra, Aaldert Hendrik</a> (2003), <a href="https://hal.archives-ouvertes.fr/in2p3-00020241/document">"The NUBASE evaluation of nuclear and decay properties"</a>, <i>Nuclear Physics A</i>, 729: 3–128, <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2003NuPhA.729....3A">2003NuPhA.729....3A</a>, <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1016%2Fj.nuclphysa.2003.11.001">10.1016/j.nuclphysa.2003.11.001</a></li> <li><a href="/facts/National_Nuclear_Data_Center/SgVzvxLk">National Nuclear Data Center</a>. <a href="http://www.nndc.bnl.gov/nudat2/">"NuDat 2.x database"</a>. <a href="/facts/Brookhaven_National_Laboratory/L2JrG0K1">Brookhaven National Laboratory</a>.</li> <li>Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). <i><a href="/facts/CRC_Handbook_of_Chemistry_and_Physics/qjxzC2Cu">CRC Handbook of Chemistry and Physics</a></i> (85th ed.). <a href="/facts/Boca_Raton%2c_Florida/9gcNen3S">Boca Raton, Florida</a>: <a href="/facts/CRC_Press/duTuH4hz">CRC Press</a>. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-0-8493-0485-9.</li></ul></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>mPa – Excited nuclear isomer. <a href="/wiki/Nuclear_isomer" target="_blank">/wiki/Nuclear_isomer</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits. <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p># – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS). <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae. <a href="https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf" target="_blank">https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p># – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN). <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae. <a href="https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf" target="_blank">https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Modes of decay: EC:Electron captureCD:Cluster decayIT:Isomeric transitionSF:Spontaneous fission <a href="/wiki/Electron_capture" target="_blank">/wiki/Electron_capture</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Bold italics symbol as daughter – Daughter product is nearly stable. <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae. <a href="https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf" target="_blank">https://www-nds.iaea.org/amdc/ame2020/NUBASE2020.pdf</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>( ) spin value – Indicates spin with weak assignment arguments. <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p># – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN). <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Zhang, M. M.; Wang, J. G.; Ma, L.; Gan, Z. G.; Zhang, Z. Y.; Huang, M. H.; Yang, H. B.; Yang, C. L.; Andreyev, A. N.; Yuan, C. X.; Tian, Y. L.; Wang, Y. S.; Wang, J. Y.; Qiang, Y. H.; Wu, X. L.; Xu, S. Y.; Zhao, Z.; Huang, X. Y.; Li, Z. C.; Zhou, H.; Zhang, X.; Xie, G.; Zhu, L.; Guan, F.; Zheng, J. H.; Sun, L. C.; Li, Y. J.; Yang, H. R.; Duan, L. M.; Lu, Z. W.; Huang, W. X.; Sun, L. T.; He, Y.; Xu, H. S.; Niu, Y. F.; He, X. T.; Ren, Z. Z.; Zhou, S. G. (29 May 2025). "Discovery of the α-emitting isotope 210Pa". Nature Communications. 16 (1): 5003. doi:10.1038/s41467-025-60047-2. ISSN 2041-1723. Retrieved 1 June 2025. <a href="https://www.nature.com/articles/s41467-025-60047-2" target="_blank">https://www.nature.com/articles/s41467-025-60047-2</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Order of ground state and isomer is uncertain. <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Intermediate decay product of 235U <a href="/wiki/Decay_product" target="_blank">/wiki/Decay_product</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Intermediate decay product of 237Np <a href="/wiki/Neptunium-237" target="_blank">/wiki/Neptunium-237</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Intermediate decay product of 238U <a href="/wiki/Uranium-238" target="_blank">/wiki/Uranium-238</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Intermediate decay product of 238U <a href="/wiki/Uranium-238" target="_blank">/wiki/Uranium-238</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001. <a href="https://www-nds.iaea.org/amdc/ame2016/NUBASE2016.pdf" target="_blank">https://www-nds.iaea.org/amdc/ame2016/NUBASE2016.pdf</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> <li id="fn:20"><p>Mastren, T.; Stein, B.W.; Parker, T.G.; Radchenko, V.; Copping, R.; Owens, A.; Wyant, L.E.; Brugh, M.; Kozimor, S.A.; Noriter, F.M.; Birnbaum, E.R.; John, K.D.; Fassbender, M.E. (2018). "Separation of protactinium employing sulfur-based extraction chromatographic resins". Analytical Chemistry. 90 (11): 7012–7017. doi:10.1021/acs.analchem.8b01380. ISSN 0003-2700. OSTI 1440455. PMID 29757620. <a href="https://www.researchgate.net/publication/325135604" target="_blank">https://www.researchgate.net/publication/325135604</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></p></li> <li id="fn:21"><p>Fry, C., and M. Thoennessen. "Discovery of the Actinium, Thorium, Protactinium, and Uranium Isotopes." January 14, 2012. Accessed May 20, 2018. https://people.nscl.msu.edu/~thoennes/2009/ac-th-pa-u-adndt.pdf. <a href="https://people.nscl.msu.edu/~thoennes/2009/ac-th-pa-u-adndt.pdf" target="_blank">https://people.nscl.msu.edu/~thoennes/2009/ac-th-pa-u-adndt.pdf</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></p></li> <li id="fn:22"><p>"Human Health Fact Sheet - Protactinium" (PDF). Argonne National Laboratory (ANL). November 2001. Retrieved 17 October 2023. <a href="http://hpschapters.org/northcarolina/NSDS/Protactinium.pdf" target="_blank">http://hpschapters.org/northcarolina/NSDS/Protactinium.pdf</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></p></li> <li id="fn:23"><p>"Human Health Fact Sheet - Protactinium" (PDF). Argonne National Laboratory (ANL). November 2001. Retrieved 17 October 2023. <a href="http://hpschapters.org/northcarolina/NSDS/Protactinium.pdf" target="_blank">http://hpschapters.org/northcarolina/NSDS/Protactinium.pdf</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></p></li> </ol>