Isotopes of radium

 ( Radium ) 

Radium (₈₈Ra) has no stable or nearly stable , and thus a standard atomic weight cannot be given. The longest lived, and most common, isotope of radium is ²²⁶Ra with a half-life of . ²²⁶Ra occurs in the decay chain of ²³⁸U (often referred to as the radium series). Radium has 34 known isotopes from ²⁰¹Ra to ²³⁴Ra.

In the early history of the study of radioactivity, the different natural isotopes of radium were given different names, as it was not until Frederick Soddy' /ref> When it was realized that all of these are isotopes of the same element, many of these names fell out of use, and "radium" came to refer to all isotopes, not just Ra, though mesothorium 1 in particular was still used for some time, with a footnote explaining that it referred to Ra. Some of radium-226's decay products received historical names including "radium", ranging from radium  to radium , with the letter indicating approximately how far they were down the chain from their parent Ra.

In 2013 it was discovered that the nucleus of radium-224 is pear-shaped. This was the first discovery of an asymmetrical nucleus.

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List of isotopes |-id=Radium-201 | ²⁰¹Ra | | style="text-align:right" | 88 | style="text-align:right" | 113 | 201.012815(22) | 20(30) ms | alpha decay | ¹⁹⁷Rn | (3/2−) | |-id=Radium-201m | style="text-indent:1em" | ^201mRa | | colspan="3" style="text-indent:2em" | 263(26) keV | 6(5) ms | α | ¹⁹⁷Rn | 13/2+ | |-id=Radium-202 | ²⁰²Ra | | style="text-align:right" | 88 | style="text-align:right" | 114 | 202.009742(16) | 4.1(11) ms | α | ¹⁹⁸Rn | 0+ | |-id=Radium-203 | ²⁰³Ra | | style="text-align:right" | 88 | style="text-align:right" | 115 | 203.009234(10) | 36(13) ms | α | ¹⁹⁹Rn | 3/2− | |-id=Radium-203m | style="text-indent:1em" | ^203mRa | | colspan="3" style="text-indent:2em" | 246(14) keV | 25(5) ms | α | ¹⁹⁹Rn | 13/2+ | |-id=Radium-204 | ²⁰⁴Ra | | style="text-align:right" | 88 | style="text-align:right" | 116 | 204.0065069(96) | 60(9) ms | α (99.7%) | ²⁰⁰Rn | 0+ | |-id=Radium-205 | ²⁰⁵Ra | | style="text-align:right" | 88 | style="text-align:right" | 117 | 205.006231(24) | 220(50) ms | α | ²⁰¹Rn | 3/2− | |-id=Radium-205m | style="text-indent:1em" | ^205mRa | | colspan="3" style="text-indent:2em" | 263(25) keV | 180(50) ms | α | ²⁰¹Rn | 13/2+ | |-id=Radium-206 | ²⁰⁶Ra | | style="text-align:right" | 88 | style="text-align:right" | 118 | 206.003828(19) | 0.24(2) s | α | ²⁰²Rn | 0+ | |-id=Radium-207 | rowspan=2|²⁰⁷Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 119 | rowspan=2|207.003772(63) | rowspan=2|1.38(18) s | α (86%) | ²⁰³Rn | rowspan=2|5/2−# | rowspan=2| |- | beta decay (14%) | ²⁰⁷Fr |-id=Radium-207m | rowspan=2 style="text-indent:1em" | ^207mRa | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 560(60) keV | rowspan=2|57(8) ms | IT (85#%) | ²⁰⁷Ra | rowspan=2|13/2+ | rowspan=2| |- | α (?%) | ²⁰³Rn |-id=Radium-208 | rowspan=2|²⁰⁸Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 120 | rowspan=2|208.0018550(97) | rowspan=2|1.110(45) s | α (87%) | ²⁰⁴Rn | rowspan=2|0+ | rowspan=2| |- | β⁺ (13%) | ²⁰⁸Fr |-id=Radium-208m | style="text-indent:1em" | ^208mRa | | colspan="3" style="text-indent:2em" | 2147.4(4) keV | 263(17) ns | IT | ²⁰⁸Ra | (8+) | |-id=Radium-209 | ²⁰⁹Ra | | style="text-align:right" | 88 | style="text-align:right" | 121 | 209.0019949(62) | 4.71(8) s | α (90%) | ²⁰⁵Rn | 5/2− | |-id=Radium-209m | rowspan=2 style="text-indent:1em" | ^209mRa | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 882.4(7) keV | rowspan=2|117(5) μs | α (90%) | ²⁰⁵Rn | rowspan=2|13/2+ | rowspan=2| |- | β⁺ (10%) | ²⁰⁹Fr |-id=Radium-210 | ²¹⁰Ra | | style="text-align:right" | 88 | style="text-align:right" | 122 | 210.0004754(99) | 4.0(1) s | α | ²⁰⁶Rn | 0+ | |-id=Radium-210m | style="text-indent:1em" | ^210mRa | | colspan="3" style="text-indent:2em" | 2050.9(7) keV | 2.29(3) μs | IT | ²¹⁰Ra | 8+ | |-id=Radium-211 | ²¹¹Ra | | style="text-align:right" | 88 | style="text-align:right" | 123 | 211.0008930(53) | 12.6(12) s | α | ²⁰⁷Rn | 5/2− | |-id=Radium-211m | style="text-indent:1em" | ^211mRa | | colspan="3" style="text-indent:2em" | 1198.1(8) keV | 9.5(3) μs | IT | ²¹¹Ra | 13/2+ | |-id=Radium-212 | rowspan=2|²¹²Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 124 | rowspan=2|211.999787(11) | rowspan=2|13.0(2) s | α (?%) | ²⁰⁸Rn | rowspan=2|0+ | rowspan=2| |- | β⁺ (?%) | ²¹²Fr |-id=Radium-212m1 | style="text-indent:1em" | ^212m1Ra | | colspan="3" style="text-indent:2em" | 1958.4(20) keV | 9.3(9) μs | IT | ²¹²Ra | 8+ | |-id=Radium-212m2 | style="text-indent:1em" | ^212m2Ra | | colspan="3" style="text-indent:2em" | 2613.3(20) keV | 0.85(13) μs | IT | ²¹²Ra | 11− | |-id=Radium-213 | rowspan=2|²¹³Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 125 | rowspan=2|213.000371(11) | rowspan=2|2.73(5) min | α (87%) | ²⁰⁹Rn | rowspan=2|1/2− | rowspan=2| |- | β⁺ (13%) | ²¹³Fr |-id=Radium-213m | rowspan=2 style="text-indent:1em" | ^213mRa | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 1768(4) keV | rowspan=2|2.20(5) ms | IT (99.4%) | ²¹³Ra | rowspan=2|(17/2−) | rowspan=2| |- | α (0.6%) | ²⁰⁹Rn |-id=Radium-214 | rowspan=2|²¹⁴Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 126 | rowspan=2|214.0000996(56) | rowspan=2|2.437(16) s | α (99.94%) | ²¹⁰Rn | rowspan=2|0+ | rowspan=2| |- | β⁺ (0.059%) | ²¹⁴Fr |-id=Radium-214m1 | style="text-indent:1em" | ^214m1Ra | | colspan="3" style="text-indent:2em" | 1819.7(18) keV | 118(7) ns | IT | ²¹⁴Ra | 6+ | |-id=Radium-214m2 | rowspan=2 style="text-indent:1em" | ^214m2Ra | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 1865.2(18) keV | rowspan=2|67.3(15) μs | IT (99.91%) | ²¹⁴Ra | rowspan=2|8+ | rowspan=2| |- | α (0.09%) | ²¹⁰Rn |-id=Radium-214m3 | style="text-indent:1em" | ^214m3Ra | | colspan="3" style="text-indent:2em" | 2683.2(18) keV | 295(7) ns | IT | ²¹⁴Ra | 11− | |-id=Radium-214m4 | style="text-indent:1em" | ^214m4Ra | | colspan="3" style="text-indent:2em" | 3478.4(18) keV | 279(4) ns | IT | ²¹⁴Ra | 14+ | |-id=Radium-214m5 | style="text-indent:1em" | ^214m5Ra | | colspan="3" style="text-indent:2em" | 4146.8(18) keV | 225(4) ns | IT | ²¹⁴Ra | 17− | |-id=Radium-214m6 | style="text-indent:1em" | ^214m6Ra | | colspan="3" style="text-indent:2em" | 6577.0(18) keV | 128(4) ns | IT | ²¹⁴Ra | (25−) | |-id=Radium-215 | ²¹⁵Ra | | style="text-align:right" | 88 | style="text-align:right" | 127 | 215.0027182(77) | 1.669(9) ms | α | ²¹¹Rn | 9/2+# | |-id=Radium-215m1 | style="text-indent:1em" | ^215m1Ra | | colspan="3" style="text-indent:2em" | 1877.8(3) keV | 7.31(13) μs | IT | ²¹⁵Ra | (25/2+) | |-id=Radium-215m2 | style="text-indent:1em" | ^215m2Ra | | colspan="3" style="text-indent:2em" | 2246.9(4) keV | 1.39(7) μs | IT | ²¹⁵Ra | (29/2−) | |-id=Radium-215m3 | style="text-indent:1em" | ^215m3Ra | | colspan="3" style="text-indent:2em" | 3807(50)# keV | 555(10) ns | IT | ²¹⁵Ra | (43/2−) | |-id=Radium-216 | rowspan=2|²¹⁶Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 128 | rowspan=2|216.0035335(86) | rowspan=2|172(7) ns | α | ²¹²Rn | rowspan=2|0+ | rowspan=2| |- | Electron capture (<1×10⁻⁸%) | ²¹⁶Fr |-id=Radium-217 | ²¹⁷Ra | | style="text-align:right" | 88 | style="text-align:right" | 129 | 217.0063227(76) | 1.95(12) μs | α | ²¹³Rn | (9/2+) | |-id=Radium-218 |²¹⁸Ra | | style="text-align:right" | 88 | style="text-align:right" | 130 | 218.007134(11) | 25.91(14) μs | α | ²¹⁴Rn | 0+ | |-id=Radium-219 | ²¹⁹Ra | | style="text-align:right" | 88 | style="text-align:right" | 131 | 219.0100847(73) | 9(2) ms | α | ²¹⁵Rn | (7/2)+ | |-id=Radium-219m | style="text-indent:1em" | ^219mRa | | colspan="3" style="text-indent:2em" | 16.7(8) keV | 10(3) ns | α | ²¹⁵Rn | (11/2)+ | |-id=Radium-220 | ²²⁰Ra | | style="text-align:right" | 88 | style="text-align:right" | 132 | 220.0110275(82) | 18.1(12) ms | α | ²¹⁶Rn | 0+ | |-id=Radium-221 | rowspan=2|²²¹Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 133 | rowspan=2|221.0139173(05) | rowspan=2|25(4) s | α | ²¹⁷Rn | rowspan=2|5/2+ | rowspan=2|TraceIntermediate decay product of ²³⁷Np |- | Cluster decay (1.2×10⁻¹⁰%)Lightest known nuclide to undergo cluster decay | ²⁰⁷Pb
¹⁴C |-id=Radium-222 | rowspan=2|²²²Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 134 | rowspan=2|222.0153734(48) | rowspan=2|33.6(4) s | α | ²¹⁸Rn | rowspan=2|0+ | rowspan=2| |- | CD (3.0×10⁻⁸%) | ²⁰⁸Pb
¹⁴C |- | rowspan=2|²²³RaUsed for treating bone cancer | rowspan=2|Actinium X | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 135 | rowspan=2|223.0185006(22) | rowspan=2|11.4352(10) d | α | ²¹⁹Rn | rowspan=2|3/2+ | rowspan=2|TraceIntermediate decay product of ²³⁵U |- | CD (8.9×10⁻⁸%) | ²⁰⁹Pb
¹⁴C |-id=Radium-224 | rowspan=2|²²⁴Ra | rowspan=2|Thorium X | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 136 | rowspan=2|224.0202104(19) | rowspan=2|3.6316(14) d | α | ²²⁰Rn | rowspan=2|0+ | rowspan=2|TraceIntermediate decay product of ²³²Th |- | CD (4.0×10⁻⁹%) | ²¹⁰Pb
¹⁴C |-id=Radium-225 | rowspan=2|²²⁵Ra | rowspan=2| | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 137 | rowspan=2|225.0236105(28) | rowspan=2|14.82(19) d | β⁻ | ²²⁵Ac | rowspan=2|1/2+ | rowspan=2|TraceIntermediate decay product of ²³⁷Np |- |α (.0026%) |²²¹Rn |- | rowspan=2|²²⁶Ra | rowspan=2|RadiumSource of element's name | rowspan=2 style="text-align:right" | 88 | rowspan=2 style="text-align:right" | 138 | rowspan=2|226.0254082(21) | rowspan=2|1600(7) y | α | ²²²Rn | rowspan=2|0+ | rowspan=2|TraceIntermediate decay product of ²³⁸U |- | CD (2.6×10⁻⁹%) | ²¹²Pb
¹⁴C |-id=Radium-227 | ²²⁷Ra | | style="text-align:right" | 88 | style="text-align:right" | 139 | 227.0291762(21) | 42.2(5) min | β⁻ | ²²⁷Ac | 3/2+ | |-id=Radium-228 | ²²⁸Ra | Mesothorium 1 | style="text-align:right" | 88 | style="text-align:right" | 140 | 228.0310686(21) | 5.75(3) y | β⁻ | ²²⁸Ac | 0+ | Trace |-id=Radium-229 | ²²⁹Ra | | style="text-align:right" | 88 | style="text-align:right" | 141 | 229.034957(17) | 4.0(2) min | β⁻ | ²²⁹Ac | 5/2+ | |-id=Radium-230 | ²³⁰Ra | | style="text-align:right" | 88 | style="text-align:right" | 142 | 230.037055(11) | 93(2) min | β⁻ | ²³⁰Ac | 0+ | |-id=Radium-231 | ²³¹Ra | | style="text-align:right" | 88 | style="text-align:right" | 143 | 231.041027(12) | 104(1) s | β⁻ | ²³¹Ac | (5/2+) | |-id=Radium-231m | style="text-indent:1em" | ^231mRa | | colspan="3" style="text-indent:2em" | 66.21(9) keV | ~53 μs | IT | ²³¹Ra | (1/2+) | |-id=Radium-232 | ²³²Ra | | style="text-align:right" | 88 | style="text-align:right" | 144 | 232.0434753(98) | 4.0(3) min | β⁻ | ²³²Ac | 0+ | |-id=Radium-233 | ²³³Ra | | style="text-align:right" | 88 | style="text-align:right" | 145 | 233.0475946(92) | 30(5) s | β⁻ | ²³³Ac | 1/2+# | |-id=Radium-234 | ²³⁴Ra | | style="text-align:right" | 88 | style="text-align:right" | 146 | 234.0503821(90) | 30(10) s | β⁻ | ²³⁴Ac | 0+ |

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Actinides vs fission products

• Isotope masses from:
• Half-life, spin, and isomer data selected from the following sources.

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Notes

Categories: Radium

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