Isotopes of radium

<h2 id="list-of-isotopes">List of isotopes</h2>

<table><tbody><tr><th rowspan="2">Nuclide<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a></th><th rowspan="2">Historicname</th><th rowspan="1"><a href="/facts/Atomic_number/bgAr581S">Z</a></th><th rowspan="1"><a href="/facts/Neutron_number/eNtwGnVL">N</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:9" href="#fn:9">9</a><a class="footnote-ref" id="fnref:10" href="#fn:10">10</a><a class="footnote-ref" id="fnref:11" href="#fn:11">11</a></th><th rowspan="2"><a href="/facts/Half-life/kGVH8BAB">Half-life</a><a class="footnote-ref" id="fnref:12" href="#fn:12">12</a></th><th rowspan="2"><a href="/facts/Decay_mode/Ya6FVjt4">Decaymode</a><a class="footnote-ref" id="fnref:13" href="#fn:13">13</a><a class="footnote-ref" id="fnref:14" href="#fn:14">14</a></th><th rowspan="2"><a href="/facts/Decay_product/hT0obfLv">Daughterisotope</a><a class="footnote-ref" id="fnref:15" href="#fn:15">15</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:16" href="#fn:16">16</a><a class="footnote-ref" id="fnref:17" href="#fn:17">17</a><a class="footnote-ref" id="fnref:18" href="#fn:18">18</a></th><th rowspan="2"><a href="/facts/Natural_abundance/dGjaAwc9">Isotopicabundance</a></th></tr><tr><th colspan="3">Excitation energy<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a></th></tr><tr><td>201Ra</td><td></td><td>88</td><td>113</td><td>201.012815(22)</td><td>20(30) ms</td><td><a href="/facts/Alpha_decay/rCsHNIUE">α</a></td><td>197Rn</td><td>(3/2−)</td><td></td></tr><tr><td>201mRa</td><td></td><td colspan="3">263(26) keV</td><td>6(5) ms</td><td>α</td><td>197Rn</td><td>13/2+</td><td></td></tr><tr><td>202Ra</td><td></td><td>88</td><td>114</td><td>202.009742(16)</td><td>4.1(11) ms</td><td>α</td><td>198Rn</td><td>0+</td><td></td></tr><tr><td>203Ra</td><td></td><td>88</td><td>115</td><td>203.009234(10)</td><td>36(13) ms</td><td>α</td><td>199Rn</td><td>3/2−</td><td></td></tr><tr><td>203mRa</td><td></td><td colspan="3">246(14) keV</td><td>25(5) ms</td><td>α</td><td>199Rn</td><td>13/2+</td><td></td></tr><tr><td>204Ra</td><td></td><td>88</td><td>116</td><td>204.0065069(96)</td><td>60(9) ms</td><td>α (99.7%)</td><td>200Rn</td><td>0+</td><td></td></tr><tr><td>205Ra</td><td></td><td>88</td><td>117</td><td>205.006231(24)</td><td>220(50) ms</td><td>α</td><td>201Rn</td><td>3/2−</td><td></td></tr><tr><td>205mRa</td><td></td><td colspan="3">263(25) keV</td><td>180(50) ms</td><td>α</td><td>201Rn</td><td>13/2+</td><td></td></tr><tr><td>206Ra</td><td></td><td>88</td><td>118</td><td>206.003828(19)</td><td>0.24(2) s</td><td>α</td><td>202Rn</td><td>0+</td><td></td></tr><tr><td rowspan="2">207Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">119</td><td rowspan="2">207.003772(63)</td><td rowspan="2">1.38(18) s</td><td>α (86%)</td><td>203Rn</td><td rowspan="2">5/2−#</td><td rowspan="2"></td></tr><tr><td><a href="/facts/Beta_decay/vxTBlckp">β+</a> (14%)</td><td>207Fr</td></tr><tr><td rowspan="2">207mRa</td><td rowspan="2"></td><td rowspan="2" colspan="3">560(60) keV</td><td rowspan="2">57(8) ms</td><td><a href="/facts/Isomeric_transition/L8DHcqnk">IT</a> (85#%)</td><td>207Ra</td><td rowspan="2">13/2+</td><td rowspan="2"></td></tr><tr><td>α (?%)</td><td>203Rn</td></tr><tr><td rowspan="2">208Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">120</td><td rowspan="2">208.0018550(97)</td><td rowspan="2">1.110(45) s</td><td>α (87%)</td><td>204Rn</td><td rowspan="2">0+</td><td rowspan="2"></td></tr><tr><td>β+ (13%)</td><td>208Fr</td></tr><tr><td>208mRa</td><td></td><td colspan="3">2147.4(4) keV</td><td>263(17) ns</td><td>IT</td><td>208Ra</td><td>(8+)</td><td></td></tr><tr><td>209Ra</td><td></td><td>88</td><td>121</td><td>209.0019949(62)</td><td>4.71(8) s</td><td>α (90%)</td><td>205Rn</td><td>5/2−</td><td></td></tr><tr><td rowspan="2">209mRa</td><td rowspan="2"></td><td rowspan="2" colspan="3">882.4(7) keV</td><td rowspan="2">117(5) μs</td><td>α (90%)</td><td>205Rn</td><td rowspan="2">13/2+</td><td rowspan="2"></td></tr><tr><td>β+ (10%)</td><td>209Fr</td></tr><tr><td>210Ra</td><td></td><td>88</td><td>122</td><td>210.0004754(99)</td><td>4.0(1) s</td><td>α</td><td>206Rn</td><td>0+</td><td></td></tr><tr><td>210mRa</td><td></td><td colspan="3">2050.9(7) keV</td><td>2.29(3) μs</td><td>IT</td><td>210Ra</td><td>8+</td><td></td></tr><tr><td>211Ra</td><td></td><td>88</td><td>123</td><td>211.0008930(53)</td><td>12.6(12) s</td><td>α</td><td>207Rn</td><td>5/2−</td><td></td></tr><tr><td>211mRa</td><td></td><td colspan="3">1198.1(8) keV</td><td>9.5(3) μs</td><td>IT</td><td>211Ra</td><td>13/2+</td><td></td></tr><tr><td rowspan="2">212Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">124</td><td rowspan="2">211.999787(11)</td><td rowspan="2">13.0(2) s</td><td>α (?%)</td><td>208Rn</td><td rowspan="2">0+</td><td rowspan="2"></td></tr><tr><td>β+ (?%)</td><td>212Fr</td></tr><tr><td>212m1Ra</td><td></td><td colspan="3">1958.4(20) keV</td><td>9.3(9) μs</td><td>IT</td><td>212Ra</td><td>8+</td><td></td></tr><tr><td>212m2Ra</td><td></td><td colspan="3">2613.3(20) keV</td><td>0.85(13) μs</td><td>IT</td><td>212Ra</td><td>11−</td><td></td></tr><tr><td rowspan="2">213Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">125</td><td rowspan="2">213.000371(11)</td><td rowspan="2">2.73(5) min</td><td>α (87%)</td><td>209Rn</td><td rowspan="2">1/2−</td><td rowspan="2"></td></tr><tr><td>β+ (13%)</td><td>213Fr</td></tr><tr><td rowspan="2">213mRa</td><td rowspan="2"></td><td rowspan="2" colspan="3">1768(4) keV</td><td rowspan="2">2.20(5) ms</td><td>IT (99.4%)</td><td>213Ra</td><td rowspan="2">(17/2−)</td><td rowspan="2"></td></tr><tr><td>α (0.6%)</td><td>209Rn</td></tr><tr><td rowspan="2">214Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">126</td><td rowspan="2">214.0000996(56)</td><td rowspan="2">2.437(16) s</td><td>α (99.94%)</td><td>210Rn</td><td rowspan="2">0+</td><td rowspan="2"></td></tr><tr><td>β+ (0.059%)</td><td>214Fr</td></tr><tr><td>214m1Ra</td><td></td><td colspan="3">1819.7(18) keV</td><td>118(7) ns</td><td>IT</td><td>214Ra</td><td>6+</td><td></td></tr><tr><td rowspan="2">214m2Ra</td><td rowspan="2"></td><td rowspan="2" colspan="3">1865.2(18) keV</td><td rowspan="2">67.3(15) μs</td><td>IT (99.91%)</td><td>214Ra</td><td rowspan="2">8+</td><td rowspan="2"></td></tr><tr><td>α (0.09%)</td><td>210Rn</td></tr><tr><td>214m3Ra</td><td></td><td colspan="3">2683.2(18) keV</td><td>295(7) ns</td><td>IT</td><td>214Ra</td><td>11−</td><td></td></tr><tr><td>214m4Ra</td><td></td><td colspan="3">3478.4(18) keV</td><td>279(4) ns</td><td>IT</td><td>214Ra</td><td>14+</td><td></td></tr><tr><td>214m5Ra</td><td></td><td colspan="3">4146.8(18) keV</td><td>225(4) ns</td><td>IT</td><td>214Ra</td><td>17−</td><td></td></tr><tr><td>214m6Ra</td><td></td><td colspan="3">6577.0(18) keV</td><td>128(4) ns</td><td>IT</td><td>214Ra</td><td>(25−)</td><td></td></tr><tr><td>215Ra</td><td></td><td>88</td><td>127</td><td>215.0027182(77)</td><td>1.669(9) ms</td><td>α</td><td>211Rn</td><td>9/2+#</td><td></td></tr><tr><td>215m1Ra</td><td></td><td colspan="3">1877.8(3) keV</td><td>7.31(13) μs</td><td>IT</td><td>215Ra</td><td>(25/2+)</td><td></td></tr><tr><td>215m2Ra</td><td></td><td colspan="3">2246.9(4) keV</td><td>1.39(7) μs</td><td>IT</td><td>215Ra</td><td>(29/2−)</td><td></td></tr><tr><td>215m3Ra</td><td></td><td colspan="3">3807(50)# keV</td><td>555(10) ns</td><td>IT</td><td>215Ra</td><td>(43/2−)</td><td></td></tr><tr><td rowspan="2">216Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">128</td><td rowspan="2">216.0035335(86)</td><td rowspan="2">172(7) ns</td><td>α</td><td>212Rn</td><td rowspan="2">0+</td><td rowspan="2"></td></tr><tr><td><a href="/facts/Electron_capture/EIccoV1u">EC</a> (<1×10−8%)</td><td>216Fr</td></tr><tr><td>217Ra</td><td></td><td>88</td><td>129</td><td>217.0063227(76)</td><td>1.95(12) μs</td><td>α</td><td>213Rn</td><td>(9/2+)</td><td></td></tr><tr><td>218Ra</td><td></td><td>88</td><td>130</td><td>218.007134(11)</td><td>25.91(14) μs</td><td>α</td><td>214Rn</td><td>0+</td><td></td></tr><tr><td>219Ra</td><td></td><td>88</td><td>131</td><td>219.0100847(73)</td><td>9(2) ms</td><td>α</td><td>215Rn</td><td>(7/2)+</td><td></td></tr><tr><td>219mRa</td><td></td><td colspan="3">16.7(8) keV</td><td>10(3) ns</td><td>α</td><td>215Rn</td><td>(11/2)+</td><td></td></tr><tr><td>220Ra</td><td></td><td>88</td><td>132</td><td>220.0110275(82)</td><td>18.1(12) ms</td><td>α</td><td>216Rn</td><td>0+</td><td></td></tr><tr><td rowspan="2">221Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">133</td><td rowspan="2">221.0139173(05)</td><td rowspan="2">25(4) s</td><td>α</td><td>217Rn</td><td rowspan="2">5/2+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a></td></tr><tr><td><a href="/facts/Cluster_decay/sIelGo3t">CD</a> (1.2×10−10%)<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a></td><td>207Pb<a href="/facts/Carbon-14/Ut8SBNNa">14C</a></td></tr><tr><td rowspan="2">222Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">134</td><td rowspan="2">222.0153734(48)</td><td rowspan="2">33.6(4) s</td><td>α</td><td>218Rn</td><td rowspan="2">0+</td><td rowspan="2"></td></tr><tr><td>CD (3.0×10−8%)</td><td>208Pb14C</td></tr><tr><td rowspan="2"><a href="/facts/Radium-223/AYDNVIFg">223Ra</a><a class="footnote-ref" id="fnref:22" href="#fn:22">22</a></td><td rowspan="2">Actinium X</td><td rowspan="2">88</td><td rowspan="2">135</td><td rowspan="2">223.0185006(22)</td><td rowspan="2">11.4352(10) d</td><td>α</td><td>219Rn</td><td rowspan="2">3/2+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a></td></tr><tr><td>CD (8.9×10−8%)</td><td>209Pb14C</td></tr><tr><td rowspan="2">224Ra</td><td rowspan="2">Thorium X</td><td rowspan="2">88</td><td rowspan="2">136</td><td rowspan="2">224.0202104(19)</td><td rowspan="2">3.6316(14) d</td><td>α</td><td>220Rn</td><td rowspan="2">0+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:24" href="#fn:24">24</a></td></tr><tr><td>CD (4.0×10−9%)</td><td>210Pb14C</td></tr><tr><td rowspan="2">225Ra</td><td rowspan="2"></td><td rowspan="2">88</td><td rowspan="2">137</td><td rowspan="2">225.0236105(28)</td><td rowspan="2">14.82(19) d</td><td>β−</td><td>225Ac</td><td rowspan="2">1/2+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:25" href="#fn:25">25</a></td></tr><tr><td>α (2.6×10−3%)<a class="footnote-ref" id="fnref:26" href="#fn:26">26</a></td><td>221Rn</td></tr><tr><td rowspan="2"><a href="/facts/Radium-226/T0SlGtRH">226Ra</a></td><td rowspan="2">Radium<a class="footnote-ref" id="fnref:27" href="#fn:27">27</a></td><td rowspan="2">88</td><td rowspan="2">138</td><td rowspan="2">226.0254082(21)</td><td rowspan="2">1600(7) y</td><td>α<a class="footnote-ref" id="fnref:28" href="#fn:28">28</a></td><td><a href="/facts/Radon-222/FTWdEQn0">222Rn</a></td><td rowspan="2">0+</td><td rowspan="2">Trace<a class="footnote-ref" id="fnref:29" href="#fn:29">29</a></td></tr><tr><td>CD (2.6×10−9%)</td><td>212Pb14C</td></tr><tr><td>227Ra</td><td></td><td>88</td><td>139</td><td>227.0291762(21)</td><td>42.2(5) min</td><td>β−</td><td>227Ac</td><td>3/2+</td><td></td></tr><tr><td>228Ra</td><td>Mesothorium 1</td><td>88</td><td>140</td><td>228.0310686(21)</td><td>5.75(3) y</td><td>β−</td><td>228Ac</td><td>0+</td><td>Trace<a class="footnote-ref" id="fnref:30" href="#fn:30">30</a></td></tr><tr><td>229Ra</td><td></td><td>88</td><td>141</td><td>229.034957(17)</td><td>4.0(2) min</td><td>β−</td><td>229Ac</td><td>5/2+</td><td></td></tr><tr><td>230Ra</td><td></td><td>88</td><td>142</td><td>230.037055(11)</td><td>93(2) min</td><td>β−</td><td>230Ac</td><td>0+</td><td></td></tr><tr><td>231Ra</td><td></td><td>88</td><td>143</td><td>231.041027(12)</td><td>104(1) s</td><td>β−</td><td>231Ac</td><td>(5/2+)</td><td></td></tr><tr><td>231mRa</td><td></td><td colspan="3">66.21(9) keV</td><td>~53 μs</td><td>IT</td><td>231Ra</td><td>(1/2+)</td><td></td></tr><tr><td>232Ra</td><td></td><td>88</td><td>144</td><td>232.0434753(98)</td><td>4.0(3) min</td><td>β−</td><td>232Ac</td><td>0+</td><td></td></tr><tr><td>233Ra</td><td></td><td>88</td><td>145</td><td>233.0475946(92)</td><td>30(5) s</td><td>β−</td><td>233Ac</td><td>1/2+#</td><td></td></tr><tr><td>234Ra</td><td></td><td>88</td><td>146</td><td>234.0503821(90)</td><td>30(10) s</td><td>β−</td><td>234Ac</td><td>0+</td><td></td></tr><tr><th colspan="20">This table header & footer: <ul><li>view</li></ul></th></tr></tbody></table>

<h2 id="actinides-vs-fission-products">Actinides vs fission products</h2>
<table><tbody><tr><th colspan="9">Actinides and fission products by half-life <ul><li>v</li><li>t</li><li>e</li></ul></th></tr><tr><th colspan="4"><a href="/facts/Actinide/kHC4lxJV">Actinides</a><a class="footnote-ref" id="fnref:31" href="#fn:31">31</a> by <a href="/facts/Decay_chain/JvTwPNBn">decay chain</a></th><th rowspan="2"><a href="/facts/Half-life/kGVH8BAB">Half-life</a> range (<a href="/facts/Year/51V242hh">a</a>)</th><th colspan="4"><a href="/facts/Fission_product/xJd9MXXH">Fission products</a> of <a href="/facts/Uranium-235/pe0RznDM">235U</a> by <a href="/facts/Fission_product_yield/5t9htHpQ">yield</a><a class="footnote-ref" id="fnref:32" href="#fn:32">32</a></th></tr><tr><th><a href="/facts/Thorium_series/JvTwPNBn">4n</a></th><th><a href="/facts/Neptunium_series/JvTwPNBn">4n + 1</a></th><th><a href="/facts/Uranium_series/JvTwPNBn">4n + 2</a></th><th><a href="/facts/Actinium_series/JvTwPNBn">4n + 3</a></th><th>4.5–7%</th><th>0.04–1.25%</th><th><0.001%</th></tr><tr><td><a href="/facts/Radium-228/T0SlGtRH">228</a>Ra№</td><td></td><td></td><td></td><th><a href="/facts/Medium-lived_fission_product/wxe6qNIp">4–6 a</a></th><td></td><td><a href="/facts/Europium-155/IUWzfhMI">155</a>Euþ</td><td></td></tr><tr><td><a href="/facts/Berkelium-248/RnvnlKK4">248</a>Bk<a class="footnote-ref" id="fnref:33" href="#fn:33">33</a></td><td></td><td></td><td></td><th><a href="/facts/Medium-lived_fission_product/wxe6qNIp">> 9 a</a></th><td></td><td></td><td></td></tr><tr><td><a href="/facts/Curium-244/WnMh6VLE">244</a>Cmƒ</td><td><a href="/facts/Plutonium-241/vUyJGFrs">241</a>Puƒ</td><td><a href="/facts/Californium-250/tX06MlFX">250</a>Cf</td><td><a href="/facts/Actinium-227/vnv59EsB">227</a>Ac№</td><th><a href="/facts/Medium-lived_fission_product/wxe6qNIp">10–29 a</a></th><td><a href="/facts/Strontium-90/VJNoC5eR">90</a>Sr</td><td><a href="/facts/Krypton-85/c32MkhnV">85</a>Kr</td><td><a href="/facts/Cadmium-113m/2F42oNDz">113m</a>Cdþ</td></tr><tr><td><a href="/facts/Uranium-232/9sPn8oCm">232</a>Uƒ</td><td></td><td><a href="/facts/Plutonium-238/JzY7TPFE">238</a>Puƒ</td><td><a href="/facts/Curium-243/WnMh6VLE">243</a>Cmƒ</td><th><a href="/facts/Medium-lived_fission_product/wxe6qNIp">29–97 a</a></th><td><a href="/facts/Cs-137/NrY5Tb6j">137</a>Cs</td><td><a href="/facts/Samarium-151/e5wQw5B0">151</a>Smþ</td><td><a href="/facts/Tin-121m/C3yupbqu">121m</a>Sn</td></tr><tr><td></td><td><a href="/facts/Californium-249/tX06MlFX">249</a>Cfƒ</td><td><a href="/facts/Americium-242m/aqoWt39B">242m</a>Amƒ</td><td></td><th>141–351 a</th><td rowspan="7" colspan="3">No fission products have a half-lifein the range of 100 a–210 ka ...</td></tr><tr><td></td><td><a href="/facts/Americium-241/HnXXm1nx">241</a>Amƒ</td><td></td><td><a href="/facts/Californium-251/tX06MlFX">251</a>Cfƒ<a class="footnote-ref" id="fnref:34" href="#fn:34">34</a></td><th>430–900 a</th></tr><tr><td></td><td></td><td><a href="/facts/Radium-226/T0SlGtRH">226</a>Ra№</td><td><a href="/facts/Berkelium-247/RnvnlKK4">247</a>Bk</td><th>1.3–1.6 ka</th></tr><tr><td><a href="/facts/Plutonium-240/kIWwdLkI">240</a>Pu</td><td><a href="/facts/Thorium-229/lRb3opzg">229</a>Th</td><td><a href="/facts/Curium-246/WnMh6VLE">246</a>Cmƒ</td><td><a href="/facts/Americium-243/aqoWt39B">243</a>Amƒ</td><th>4.7–7.4 ka</th></tr><tr><td></td><td><a href="/facts/Curium-245/WnMh6VLE">245</a>Cmƒ</td><td><a href="/facts/Curium-250/WnMh6VLE">250</a>Cm</td><td></td><th>8.3–8.5 ka</th></tr><tr><td></td><td></td><td></td><td><a href="/facts/Plutonium-239/eRobTXos">239</a>Puƒ</td><th>24.1 ka</th></tr><tr><td></td><td></td><td><a href="/facts/Thorium-230/lRb3opzg">230</a>Th№</td><td><a href="/facts/Protactinium-231/AVGw4A8U">231</a>Pa№</td><th>32–76 ka</th></tr><tr><td><a href="/facts/Neptunium-236/X3bPWwX1">236</a>Npƒ</td><td><a href="/facts/Uranium-233/a6sMrk07">233</a>Uƒ</td><td><a href="/facts/Uranium-234/nKrs059u">234</a>U№</td><td></td><th><a href="/facts/Long-lived_fission_product/wxe6qNIp">150–250 ka</a></th><td><a href="/facts/Technetium-99/0w2EE0G2">99</a>Tc₡</td><td><a href="/facts/Tin-126/C3yupbqu">126</a>Sn</td></tr><tr><td><a href="/facts/Curium-248/WnMh6VLE">248</a>Cm</td><td></td><td><a href="/facts/Plutonium-242/o1fg0sBh">242</a>Pu</td><td></td><th><a href="/facts/Long-lived_fission_product/wxe6qNIp">327–375 ka</a></th><td></td><td><a href="/facts/Selenium-79/3TDcPNTR">79</a>Se₡</td></tr><tr><td></td><td></td><td></td><td></td><th><a href="/facts/Long-lived_fission_product/wxe6qNIp">1.33 Ma</a></th><td><a href="/facts/Caesium-135/m5AYV9tp">135</a>Cs₡</td></tr><tr><td></td><td><a href="/facts/Neptunium-237/X3bPWwX1">237</a>Npƒ</td><td></td><td></td><th><a href="/facts/Long-lived_fission_product/wxe6qNIp">1.61–6.5 Ma</a></th><td><a href="/facts/Zirconium-93/NzDqkTRf">93</a>Zr</td><td><a href="/facts/Palladium-107/deN3NNeY">107</a>Pd</td></tr><tr><td><a href="/facts/Uranium-236/1JepNWSb">236</a>U</td><td></td><td></td><td><a href="/facts/Curium-247/WnMh6VLE">247</a>Cmƒ</td><th><a href="/facts/Long-lived_fission_product/wxe6qNIp">15–24 Ma</a></th><td></td><td><a href="/facts/Iodine-129/oJDlGf5H">129</a>I₡</td></tr><tr><td><a href="/facts/Plutonium-244/XGtUVghF">244</a>Pu</td><td></td><td></td><td></td><th>80 Ma</th><td colspan="3" rowspan="2">... nor beyond 15.7 Ma<a class="footnote-ref" id="fnref:35" href="#fn:35">35</a></td></tr><tr><td><a href="/facts/Thorium-232/lRb3opzg">232</a>Th№</td><td></td><td><a href="/facts/Uranium-238/QhcHm6q8">238</a>U№</td><td><a href="/facts/Uranium-235/pe0RznDM">235</a>Uƒ№</td><th>0.7–14.1 Ga</th></tr><tr><td colspan="9"><ul><li>₡,  has thermal <a href="/facts/Neutron_capture/elsFpM12">neutron capture</a> cross section in the range of 8–50 barns</li><li>ƒ,  <a href="/facts/Fissile/XJR9qoxW">fissile</a></li><li>№,  primarily a <a href="/facts/Naturally_occurring_radioactive_material/oUbIxWlg">naturally occurring radioactive material</a> (NORM)</li><li>þ,  <a href="/facts/Neutron_poison/bkruR3yz">neutron poison</a> (thermal neutron capture cross section greater than 3k barns)</li></ul></td></tr></tbody></table>

<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>, Nuclear Physics A, 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>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>, Nuclear Physics A, 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.). <a href="/facts/CRC_Handbook_of_Chemistry_and_Physics/qjxzC2Cu">CRC Handbook of Chemistry and Physics</a> (85th ed.). <a href="/facts/Boca_Raton,_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>
<h3>Notes</h3>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Nagel, Miriam C. (September 1982). "Frederick Soddy: From alchemy to isotopes". Journal of Chemical Education. 59 (9): 739. Bibcode:1982JChEd..59..739N. doi:10.1021/ed059p739. ISSN 0021-9584. <a href="https://pubs.acs.org/doi/abs/10.1021/ed059p739" target="_blank">https://pubs.acs.org/doi/abs/10.1021/ed059p739</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Kirby, H.W. & Salutsky, Murrell L. (December 1964). The Radiochemistry of Radium (Report). crediting UNT Libraries Government Documents Department. p. 3 – via University of North Texas, UNT Digital Library. Alternate source: https://sgp.fas.org/othergov/doe/lanl/lib-www/books/rc000041.pdf <a href="https://digital.library.unt.edu/ark:/67531/metadc1027502/" target="_blank">https://digital.library.unt.edu/ark:/67531/metadc1027502/</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Giunta, Carmen J. (2017). "ISOTOPES: IDENTIFYING THE BREAKTHROUGH PUBLICATION (1)" (PDF). Bull. Hist. Chem. 42 (2): 103–111. <a href="https://acshist.scs.illinois.edu/awards/OPA%20Papers/2017-Giunta.pdf" target="_blank">https://acshist.scs.illinois.edu/awards/OPA%20Papers/2017-Giunta.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Looney, William B. (1958). "Effects of Radium in Man". Science. 127 (3299): 630–633. Bibcode:1958Sci...127..630L. doi:10.1126/science.127.3299.630. ISSN 0036-8075. JSTOR 1755774. PMID 13529029. <a href="https://www.jstor.org/stable/1755774" target="_blank">https://www.jstor.org/stable/1755774</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">Mitchell, S. A. "Is Radium in the Sun?". Popular Astronomy. 21: 321–331. Bibcode:1913PA.....21..321M. <a href="https://adsabs.harvard.edu/full/1913PA.....21..321M" target="_blank">https://adsabs.harvard.edu/full/1913PA.....21..321M</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Radium emanation = 222Rn, Ra A = 218Po, Ra B = 214Pb, Ra C = 214Bi, Ra C1 = 214Po, Ra C2 = 210Tl, Ra D = 210Pb, Ra E = 210Bi, Ra F = 210Po, and Ra G = 206Pb.[8][9] <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">Hills, Stephanie (8 May 2013). "First observations of short-lived pear-shaped atomic nuclei". CERN. <a href="https://home.cern/about/updates/2013/05/first-observations-short-lived-pear-shaped-atomic-nuclei" target="_blank">https://home.cern/about/updates/2013/05/first-observations-short-lived-pear-shaped-atomic-nuclei</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">mRa – Excited nuclear isomer. <a href="/wiki/Nuclear_isomer" target="_blank">/wiki/Nuclear_isomer</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">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:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits. <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11"># – 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:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">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:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">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:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Modes of decay:
EC:Electron captureCD:Cluster decayIT:Isomeric transition <a href="/wiki/Electron_capture" target="_blank">/wiki/Electron_capture</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">Bold symbol as daughter – Daughter product is stable. <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">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:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">( ) spin value – Indicates spin with weak assignment arguments. <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18"># – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN). <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19"># – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN). <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">Intermediate decay product of 237Np <a href="/wiki/Neptunium-237" target="_blank">/wiki/Neptunium-237</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">Lightest known nuclide to undergo cluster decay <a href="/wiki/Cluster_decay" target="_blank">/wiki/Cluster_decay</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">Used for treating bone cancer <a href="/wiki/Radium-223#Medical_use" target="_blank">/wiki/Radium-223#Medical_use</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Intermediate decay product of 235U <a href="/wiki/Decay_product" target="_blank">/wiki/Decay_product</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">Intermediate decay product of 232Th <a href="/wiki/Thorium-232" target="_blank">/wiki/Thorium-232</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">Intermediate decay product of 237Np <a href="/wiki/Neptunium-237" target="_blank">/wiki/Neptunium-237</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
<li id="fn:26">Liang, C. F.; Paris, P.; Sheline, R. K. (2000-09-19). "α decay of 225Ra". Physical Review C. 62 (4). American Physical Society (APS): 047303. Bibcode:2000PhRvC..62d7303L. doi:10.1103/physrevc.62.047303. ISSN 0556-2813. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></li>
<li id="fn:27">Source of element's name <a href="#fnref:27" class="footnote-back-ref">↩</a></li>
<li id="fn:28">Theoretically capable of β−β− decay to 226Th <a href="#fnref:28" class="footnote-back-ref">↩</a></li>
<li id="fn:29">Intermediate decay product of 238U <a href="/wiki/Uranium-238" target="_blank">/wiki/Uranium-238</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></li>
<li id="fn:30">Intermediate decay product of 232Th <a href="/wiki/Thorium-232" target="_blank">/wiki/Thorium-232</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></li>
<li id="fn:31">Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here. <a href="/wiki/Polonium" target="_blank">/wiki/Polonium</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></li>
<li id="fn:32">Specifically from thermal neutron fission of uranium-235, e.g. in a typical nuclear reactor. <a href="/wiki/Thermal_neutron" target="_blank">/wiki/Thermal_neutron</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></li>
<li id="fn:33">Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4."The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]." <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></li>
<li id="fn:34">This is the heaviest nuclide with a half-life of at least four years before the "sea of instability". <a href="/wiki/Sea_of_instability" target="_blank">/wiki/Sea_of_instability</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></li>
<li id="fn:35">Excluding those "classically stable" nuclides with half-lives significantly in excess of 232Th; e.g., while 113mCd has a half-life of only fourteen years, that of 113Cd is eight quadrillion years. <a href="/wiki/Primordial_nuclide" target="_blank">/wiki/Primordial_nuclide</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></li>
</ol>

Isotopes of radium open-in-new

Isotopes of radium