Isotopes of polonium

There are 42 known isotopes of polonium (₈₄Po), all radioactive, stretching from ¹⁸⁶Po to ²²⁷Po. The isotopes 210 through 218 occur naturally in the four principal decay chains; of these, ²¹⁰Po with a half-life of 138.376 days has the longest half-life and is, therefore, the most abundant by mass. It is also the most easily synthesized isotope, by neutron capture on natural bismuth, and so by far the most abundant artificial isotope as well.

Two other isotopes have longer lives: ²⁰⁹Po with a half-life of 124 years and ²⁰⁸Po with a half-life of 2.898 years. Both are made by using a cyclotron to bombard bismuth with protons.

List of isotopes

|-id=Polonium-186 | ¹⁸⁶Po | | style="text-align:right" | 84 | style="text-align:right" | 102 | 186.004403(20) | <br/> | α | ¹⁸²Pb | 0+ | |-id=Polonium-187 | ¹⁸⁷Po | | style="text-align:right" | 84 | style="text-align:right" | 103 | 187.003030(40) | 1.40(25)&nbsp;ms | α | ¹⁸³Pb | 1/2−, 5/2− | |-id=Polonium-187m | style="text-indent:1em" | ^187mPo | | colspan="3" style="text-indent:2em" | 4(27)&nbsp;keV | 0.5&nbsp;ms | α | ¹⁸³Pb | 13/2+# | |-id=Polonium-188 | ¹⁸⁸Po | | style="text-align:right" | 84 | style="text-align:right" | 104 | 187.999416(21) | 270(30)&nbsp;μs | α | ¹⁸⁴Pb | 0+ | |-id=Polonium-189 | ¹⁸⁹Po | | style="text-align:right" | 84 | style="text-align:right" | 105 | 188.998473(24) | 3.5(5)&nbsp;ms | α | ¹⁸⁵Pb | (5/2−) | |-id=Polonium-190 | ¹⁹⁰Po | | style="text-align:right" | 84 | style="text-align:right" | 106 | 189.995102(14) | 2.45(5)&nbsp;ms | α | ¹⁸⁶Pb | 0+ | |-id=Polonium-191 | ¹⁹¹Po | | style="text-align:right" | 84 | style="text-align:right" | 107 | 190.994558(8) | 22(1)&nbsp;ms | α | ¹⁸⁷Pb | 3/2− | |-id=Polonium-191m | style="text-indent:1em" | ^191mPo | | colspan="3" style="text-indent:2em" | 61(11)&nbsp;keV | 93(3)&nbsp;ms | α | ^187mPb | 13/2+ | |-id=Polonium-192 | ¹⁹²Po | | style="text-align:right" | 84 | style="text-align:right" | 108 | 191.991340(11) | 32.2(3)&nbsp;ms | α | ¹⁸⁸Pb | 0+ | |-id=Polonium-192m | style="text-indent:1em" | ^192mPo | | colspan="3" style="text-indent:2em" | 2294.6(10)&nbsp;keV | 580(100)&nbsp;ns | IT | ¹⁹²Po | 11− | |-id=Polonium-193 | ¹⁹³Po | | style="text-align:right" | 84 | style="text-align:right" | 109 | 192.991062(16) | 399(34)&nbsp;ms | α | ¹⁸⁹Pb | 3/2− | |-id=Polonium-193m | style="text-indent:1em" | ^193mPo | | colspan="3" style="text-indent:2em" | 100(6)&nbsp;keV | 245(11)&nbsp;ms | α | ^189mPb | 13/2+ | |-id=Polonium-194 | ¹⁹⁴Po | | style="text-align:right" | 84 | style="text-align:right" | 110 | 193.988186(14) | 392(4)&nbsp;ms | α | ¹⁹⁰Pb | 0+ | |-id=Polonium-194m | style="text-indent:1em" | ^194mPo | | colspan="3" style="text-indent:2em" | 2313.4(3)&nbsp;keV | 12.9(5)&nbsp;μs | IT | ¹⁹⁴Po | (10−) | |-id=Polonium-195 | rowspan=2|¹⁹⁵Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 111 | rowspan=2| 194.988066(6) | rowspan=2|4.64(9)&nbsp;s | α (94%) | ¹⁹¹Pb | rowspan=2|3/2− | rowspan=2| |- | β⁺ (6%) | ¹⁹⁵Bi |-id=Polonium-195m | style="text-indent:1em" | ^195mPo | | colspan="3" style="text-indent:2em" | 148(9)&nbsp;keV | 1.92(2)&nbsp;s | α | ^191mPb | 13/2+ | |-id=Polonium-196 | rowspan=2|¹⁹⁶Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 112 | rowspan=2|195.985541(6) | rowspan=2|5.63(7)&nbsp;s | α (94%) | ¹⁹²Pb | rowspan=2|0+ | rowspan=2| |- | β⁺ (6%) | ¹⁹⁶Bi |-id=Polonium-196m | style="text-indent:1em" | ^196mPo | | colspan="3" style="text-indent:2em" | 2493.9(4)&nbsp;keV | 856(17)&nbsp;ns | IT | ¹⁹⁶Po | 11− | |-id=Polonium-197 | rowspan=2|¹⁹⁷Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 113 | rowspan=2|196.985622(11) | rowspan=2|53.6(9)&nbsp;s | β⁺ (56%) | ¹⁹⁷Bi | rowspan=2|(3/2−) | rowspan=2| |- | α (44%) | ¹⁹³Pb |-id=Polonium-197m | rowspan=3 style="text-indent:1em" | ^197mPo | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 196(12)&nbsp;keV | rowspan=3|25.8(1)&nbsp;s | α (84%) | ^193mPb | rowspan=3|13/2+ | rowspan=3| |- | β⁺ ? | ¹⁹⁷Bi |- | IT ? | ¹⁹⁷Po |-id=Polonium-198 | rowspan=2|¹⁹⁸Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 114 | rowspan=2|197.983389(19) | rowspan=2|1.760(24)&nbsp;min | α (57%) | ¹⁹⁴Pb | rowspan=2|0+ | rowspan=2| |- | β⁺ (43%) | ¹⁹⁸Bi |-id=Polonium-198m1 | style="text-indent:1em" | ^198m1Po | | colspan="3" style="text-indent:2em" | 2565.92(20)&nbsp;keV | 200(20)&nbsp;ns | IT | ¹⁹⁸Po | 11− | |-id=Polonium-198m2 | style="text-indent:1em" | ^198m2Po | | colspan="3" style="text-indent:2em" | 2740(50)#&nbsp;keV | 750(50)&nbsp;ns | IT | ¹⁹⁸Po | 12+ | |-id=Polonium-199 | rowspan=2|¹⁹⁹Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 115 | rowspan=2|198.983640(6) | rowspan=2|5.47(15)&nbsp;min | β⁺ (92.5%) | ¹⁹⁹Bi | rowspan=2|3/2− | rowspan=2| |- | α (7.5%) | ¹⁹⁵Pb |-id=Polonium-199m | rowspan=3 style="text-indent:1em" | ^199mPo | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 311.7(27)&nbsp;keV | rowspan=3|4.17(5)&nbsp;min | β⁺ (73.5%) | ¹⁹⁹Bi | rowspan=3|13/2+ | rowspan=3| |- | α (24%) | ¹⁹⁵Pb |- | IT (2.5%) | ¹⁹⁹Po |-id=Polonium-200 | rowspan=2|²⁰⁰Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 116 | rowspan=2|199.981812(8) | rowspan=2|11.51(8)&nbsp;min | β⁺ (88.9%) | ²⁰⁰Bi | rowspan=2|0+ | rowspan=2| |- | α (11.1%) | ¹⁹⁶Pb |-id=Polonium-200m1 | style="text-indent:1em" | ^200m1Po | | colspan="3" style="text-indent:2em" | 2596.1(3)&nbsp;keV | 100(10)&nbsp;ns | IT | ²⁰⁰Po | 11- | |-id=Polonium-200m2 | style="text-indent:1em" | ^200m2Po | | colspan="3" style="text-indent:2em" | 2817(7)&nbsp;keV | 268(3)&nbsp;ns | IT | ²⁰⁰Po | 12+ | |-id=Polonium-201 | rowspan=2|²⁰¹Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 117 | rowspan=2|200.982264(5) | rowspan=2|15.6(1)&nbsp;min | β⁺ (98.87%) | ²⁰¹Bi | rowspan=2|3/2− | rowspan=2| |- | α (1.13%) | ¹⁹⁷Pb |-id=Polonium-201m | rowspan=3 style="text-indent:1em" | ^201mPo | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 423.8(24)&nbsp;keV | rowspan=3|8.96(12)&nbsp;min | IT (56.2(12)%) | ²⁰¹Po | rowspan=3|13/2+ | rowspan=3| |- | β⁺ (41.4(7)%) | ²⁰¹Bi |- | α (2.4(5)%) | ¹⁹⁷Pb |-id=Polonium-202 | rowspan=2|²⁰²Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 118 | rowspan=2|201.980739(9) | rowspan=2|44.6(4)&nbsp;min | β⁺ (98.08%) | ²⁰²Bi | rowspan=2|0+ | rowspan=2| |- | α (1.92%) | ¹⁹⁸Pb |-id=Polonium-202m | style="text-indent:1em" | ^202mPo | | colspan="3" style="text-indent:2em" | 1712(12)&nbsp;keV | 110(15)&nbsp;ns | IT | ²⁰²Po | 8+ | |-id=Polonium-203 | rowspan=2|²⁰³Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 119 | rowspan=2|202.981416(5) | rowspan=2|36.7(5)&nbsp;min | β⁺ (99.89%) | ²⁰³Bi | rowspan=2|5/2− | rowspan=2| |- | α (0.11%) | ¹⁹⁹Pb |-id=Polonium-203m1 | rowspan=2 style="text-indent:1em" | ^203m1Po | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 641.68(14)&nbsp;keV | rowspan=2|45(2)&nbsp;s | IT | ²⁰³Po | rowspan=2|13/2+ | rowspan=2| |- | α ? | ¹⁹⁹Pb |-id=Polonium-203m2 | style="text-indent:1em" | ^203m2Po | | colspan="3" style="text-indent:2em" | 2158.5(6)&nbsp;keV | >200&nbsp;ns | IT | ²⁰³Po | | |-id=Polonium-204 | rowspan=2|²⁰⁴Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 120 | rowspan=2|203.980310(11) | rowspan=2|3.519(12)&nbsp;h | β⁺ (99.33%) | ²⁰⁴Bi | rowspan=2|0+ | rowspan=2| |- | α (0.67%) | ²⁰⁰Pb |-id=Polonium-204m | style="text-indent:1em" | ^204mPo | | colspan="3" style="text-indent:2em" | 1639.03(6)&nbsp;keV | 158.6(18)&nbsp;ns | IT | ²⁰⁸Po | 8+ | |-id=Polonium-205 | rowspan=2|²⁰⁵Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 121 | rowspan=2|204.981190(11) | rowspan=2|1.74(8)&nbsp;h | β⁺ (99.96%) | ²⁰⁵Bi | rowspan=2|5/2− | rowspan=2| |- | α (0.04%) | ²⁰¹Pb |-id=Polonium-205m1 | style="text-indent:1em" | ^205m1Po | | colspan="3" style="text-indent:2em" | 143.166(15)&nbsp;keV | 310(60)&nbsp;ns | IT | ²⁰⁵Po | 1/2− | |-id=Polonium-205m2 | style="text-indent:1em" | ^205m2Po | | colspan="3" style="text-indent:2em" | 880.31(4)&nbsp;keV | 645(20)&nbsp;μs | IT | ²⁰⁵Po | 13/2+ | |-id=Polonium-205m3 | style="text-indent:1em" | ^205m3Po | | colspan="3" style="text-indent:2em" | 1461.21(21)&nbsp;keV | 57.4(9)&nbsp;ms | IT | ²⁰⁵Po | 19/2− | |-id=Polonium-205m4 | style="text-indent:1em" | ^205m4Po | | colspan="3" style="text-indent:2em" | 3087.2(4)&nbsp;keV | 115(10)&nbsp;ns | IT | ²⁰⁵Po | 29/2− | |-id=Polonium-206 | rowspan=2|²⁰⁶Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 122 | rowspan=2|205.980474(4) | rowspan=2|8.8(1)&nbsp;d | β⁺ (94.55%) | ²⁰⁶Bi | rowspan=2|0+ | rowspan=2| |- | α (5.45%) | ²⁰²Pb |-id=Polonium-206m1 | style="text-indent:1em" | ^206m1Po | | colspan="3" style="text-indent:2em" | 1585.90(11)&nbsp;keV | 232(4)&nbsp;ns | IT | ²⁰⁶Po | 8+ | |-id=Polonium-206m2 | style="text-indent:1em" | ^206m2Po | | colspan="3" style="text-indent:2em" | 2262.09(12)&nbsp;keV | 1.05(6)&nbsp;μs | IT | ²⁰⁶Po | 9− | |-id=Polonium-207 | rowspan=2|²⁰⁷Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 123 | rowspan=2|206.981593(7) | rowspan=2|5.80(2)&nbsp;h | β⁺ (99.979%) | ²⁰⁷Bi | rowspan=2|5/2− | rowspan=2| |- | α (0.021%) | ²⁰³Pb |-id=Polonium-207m1 | style="text-indent:1em" | ^207m1Po | | colspan="3" style="text-indent:2em" | 68.557(14)&nbsp;keV | 205(10)&nbsp;ns | IT | ²⁰⁷Po | 1/2− | |-id=Polonium-207m2 | style="text-indent:1em" | ^207m2Po | | colspan="3" style="text-indent:2em" | 1115.076(17)&nbsp;keV | 49(4)&nbsp;μs | IT | ²⁰⁷Po | 13/2+ | |-id=Polonium-207m3 | style="text-indent:1em" | ^207m3Po | | colspan="3" style="text-indent:2em" | 1383.16(7)&nbsp;keV | 2.79(8)&nbsp;s | IT | ²⁰⁷Po | 19/2− | |-id=Polonium-208 | rowspan=2|²⁰⁸Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 124 | rowspan=2|207.9812460(18) | rowspan=2|2.898(2)&nbsp;y | α | ²⁰⁴Pb | rowspan=2|0+ | rowspan=2| |- | β⁺ (0.0042%) | ²⁰⁸Bi |-id=Polonium-208m | style="text-indent:1em" | ^208mPo | | colspan="3" style="text-indent:2em" | 1528.22(4)&nbsp;keV | 373(8)&nbsp;ns | IT | ²⁰⁸Po | 8+ | |-id=Polonium-209 | rowspan=2|²⁰⁹Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 125 | rowspan=2|208.9824304(19) | rowspan=2|124(3)&nbsp;y | α (99.546%) | ²⁰⁵Pb | rowspan=2|1/2− | rowspan=2| |- | β⁺ (0.454%) | ²⁰⁹Bi |-id=Polonium-209m | style="text-indent:1em" | ^209mPo | | colspan="3" style="text-indent:2em" | 4265.4(3)&nbsp;keV | 119(4)&nbsp;ns | IT | ²⁰⁹Po | 31/2− | |- | ²¹⁰Po | Radium F | style="text-align:right" | 84 | style="text-align:right" | 126 | 209.9828737(12) | 138.376(2)&nbsp;d | α | ²⁰⁶Pb | 0+ | Trace |-id=Polonium-210m1 | style="text-indent:1em" | ^210m1Po | | colspan="3" style="text-indent:2em" | 1556.97(3)&nbsp;keV | 98.9(25)&nbsp;ns | IT | ²¹⁰Po | 8+ | |-id=Polonium-210m2 | style="text-indent:1em" | ^210m2Po | | colspan="3" style="text-indent:2em" | 5057.65(5)&nbsp;keV | 263(5)&nbsp;ns | IT | ²¹⁰Po | 16+ | |-id=Polonium-211 | ²¹¹Po | Actinium C' | style="text-align:right" | 84 | style="text-align:right" | 127 | 210.9866532(13) | 516(3)&nbsp;ms | α | ²⁰⁷Pb | 9/2+ | Trace |-id=Polonium-211m1 | rowspan=2 style="text-indent:1em" | ^211m1Po | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 1462(5)&nbsp;keV | rowspan=2|25.2(6)&nbsp;s | α (99.984%) | ²⁰⁷Pb | rowspan=2|(25/2+) | rowspan=2| |- | IT (0.016%) | ²¹¹Po |-id=Polonium-211m2 | style="text-indent:1em" | ^211m2Po | | colspan="3" style="text-indent:2em" | 2135(5)&nbsp;keV | 243(21)&nbsp;ns | IT | ²¹¹Po | (31/2−) | |-id=Polonium-211m3 | style="text-indent:1em" | ^211m3Po | | colspan="3" style="text-indent:2em" | 4872(6)&nbsp;keV | 2.8(7)&nbsp;μs | IT | ²¹¹Po | (43/2+) | |-id=Polonium-212 | ²¹²Po | Thorium C' | style="text-align:right" | 84 | style="text-align:right" | 128 | 211.9888680(12) | 294.4(8)&nbsp;ns | α | ²⁰⁸Pb | 0+ | Trace |-id=Polonium-212m | rowspan=2 style="text-indent:1em" | ^212mPo | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 2923(4)&nbsp;keV | rowspan=2|45.1(6)&nbsp;s | α (99.93%) | ²⁰⁸Pb | rowspan=2|(18+) | rowspan=2| |- | IT (0.07%) | ²¹²Po |-id=Polonium-213 | ²¹³Po | | style="text-align:right" | 84 | style="text-align:right" | 129 | 212.992857(3) | 3.705(1)&nbsp;μs | α | ²⁰⁹Pb | 9/2+ | Trace |-id=Polonium-214 | ²¹⁴Po | Radium C' | style="text-align:right" | 84 | style="text-align:right" | 130 | 213.9952013(16) | 163.47(3)&nbsp;μs | α | ²¹⁰Pb | 0+ | Trace |-id=Polonium-215 | rowspan=2|²¹⁵Po | rowspan=2|Actinium A | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 131 | rowspan=2|214.9994184(23) | rowspan=2|1.781(5)&nbsp;ms | α | ²¹¹Pb | rowspan=2|9/2+ | rowspan=2|Trace |- | β^− (2.3×10^{−4}%) | ²¹⁵At |-id=Polonium-216 | ²¹⁶Po | Thorium A | style="text-align:right" | 84 | style="text-align:right" | 132 | 216.0019134(19) | 143.7(5)&nbsp;ms | α | ²¹²Pb | 0+ | Trace |-id=Polonium-217 | rowspan=2|²¹⁷Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 133 | rowspan=2|217.006316(7) | rowspan=2|1.53(5)&nbsp;s | α (97.5%) | ²¹³Pb | rowspan=2|(9/2+) | rowspan=2|Trace |- | β^− (2.5%) | ²¹⁷At |-id=Polonium-218 | rowspan=2|²¹⁸Po | rowspan=2|Radium A | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 134 | rowspan=2|218.0089712(21) | rowspan=2|3.097(12)&nbsp;min | α (99.98%) | ²¹⁴Pb | rowspan=2|0+ | rowspan=2|Trace |- | β^− (0.02%) | ²¹⁸At |-id=Polonium-219 | rowspan=2|²¹⁹Po | rowspan=2| | rowspan=2 style="text-align:right" | 84 | rowspan=2 style="text-align:right" | 135 | rowspan=2|219.013614(17) | rowspan=2|10.3(10)&nbsp;min | β^− (71.8%) | ²¹⁹At | rowspan=2|9/2+# | rowspan=2| |- | α (28.2%) | ²¹⁵Pb |-id=Polonium-220 | ²²⁰Po | | style="text-align:right" | 84 | style="text-align:right" | 136 | 220.016386(19) | 10# s<br>[>300&nbsp;ns] | β^− ? | ²²⁰At | 0+ | |-id=Polonium-221 | ²²¹Po | | style="text-align:right" | 84 | style="text-align:right" | 137 | 221.021228(21) | 2.2 +/- 0.7 min | β^− | ²²¹At | 9/2+# | |-id=Polonium-222 | ²²²Po | | style="text-align:right" | 84 | style="text-align:right" | 138 | 222.02414(4) | 9.1 +/- 7.2 min | β^− | ²²²At | 0+ | |-id=Polonium-223 | ²²³Po | | style="text-align:right" | 84 | style="text-align:right" | 139 | 223.02907(21)# | 6#&nbsp;s<br>[>300&nbsp;ns] | β^− ? | ²²³At | 11/2+# | |-id=Polonium-224 | ²²⁴Po | | style="text-align:right" | 84 | style="text-align:right" | 140 | 224.03211(21)# | 3#&nbsp;min<br>[>300&nbsp;ns] | β^− ? | ²²⁴At | 0+ | |-id=Polonium-225 | ²²⁵Po | | style="text-align:right" | 84 | style="text-align:right" | 141 | 225.03712(32)# | 10#&nbsp;s<br>[>300&nbsp;ns] | β^− ? | ²²⁵At | 3/2+# | |-id=Polonium-226 | ²²⁶Po | | style="text-align:right" | 84 | style="text-align:right" | 142 | 226.04031(43)# | 1#&nbsp;min<br>[>300&nbsp;ns] | β^− ? | ²²⁶At | 0+ | |-id=Polonium-227 | ²²⁷Po | | style="text-align:right" | 84 | style="text-align:right" | 143 | 227.04539(43)# | 2#&nbsp;s<br>[>300&nbsp;ns] | β^− ? | ²²⁷At | 5/2+# |

Daughter products other than polonium

• Isotopes of astatine
• Isotopes of bismuth
• Isotopes of lead

References