Isotopes of francium

{{Short description|none}} {{Infobox francium isotopes}} Francium (₈₇Fr) has no stable isotopes, so a standard atomic weight cannot be given. Its most stable isotope is ²²³Fr with a half-life of 22 minutes, occurring in trace quantities in nature as an intermediate decay product of ²³⁵U.

Of elements whose most stable isotopes have been identified with certainty, francium is the most unstable, though astatine is the rarest in nature due to its naturally occurring isotopes having even shorter half-lives and even smaller branching ratios.

The elements with atomic number of 106 (seaborgium) or greater have their longest known half-life of any isotope shorter than that of francium, but as those elements have only isotopes on the proton-rich side of beta stability discovered, there is a strong possibility that undiscovered isotopes of these elements will have longer half-lives that could exceed that of francium-223.

== List of isotopes == {{Anchor}}

<!--Please delete anchor(s) from the list above or table below if adding a dedicated isotope section(s).-->

{{Isotopes table |symbol=Fr |refs=NUBASE2020, AME2020 II,<!-- updated 2025-07-18 --> IsotopeFRIB, IsomerFRIB |notes=m, histname, unc(), mass#, exen#, hl#, spin(), spin#, A, B+, B-, IT, CD, discoveryname }} |-id=Francium-197 | ¹⁹⁷Fr | | style="text-align:right" | 87 | style="text-align:right" | 110 | 197.01101(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/197.pdf 2013] | 2.3(19)&nbsp;ms | α | ¹⁹³At | (7/2−) | |-id=Francium-198 | ¹⁹⁸Fr | | style="text-align:right" | 87 | style="text-align:right" | 111 | 198.01028(3) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/198.pdf 2013] | 15(3)&nbsp;ms | α | ¹⁹⁴At | 3+# | |-id=Francium-198m | style="text-indent:1em" | ^198mFr<ref group="n" name="order">Order of ground state and isomer is uncertain.</ref> | | colspan="3" style="text-indent:2em" | 0(50)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/198Fr-1.pdf 2013] | 1.1(7)&nbsp;ms | α | ¹⁹⁴At | (10−) | |-id=Francium-199 | ¹⁹⁹Fr | | style="text-align:right" | 87 | style="text-align:right" | 112 | 199.007269(15) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/199.pdf 1999] | 6.6(22)&nbsp;ms | α | ¹⁹⁵At | 1/2+# | |-id=Francium-199m1 | style="text-indent:1em" | ^199m1Fr | | colspan="3" style="text-indent:2em" | 45(13)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/199Fr-1.pdf 2013] | 6.5(9)&nbsp;ms | α | ¹⁹⁵At | 7/2−# | |-id=Francium-199m2 | style="text-indent:1em" | ^199m2Fr | | colspan="3" style="text-indent:2em" | 250(50)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/199Fr-2.pdf 2013] | 2.2(12)&nbsp;ms | α | ¹⁹⁵At | 13/2+# | |-id=Francium-200 | ²⁰⁰Fr | | style="text-align:right" | 87 | style="text-align:right" | 113 | 200.00658(3) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/200.pdf 1995] | 47.5(28)&nbsp;ms | α | ¹⁹⁶At | (3+) | |-id=Francium-200m1 | style="text-indent:1em" | ^200m1Fr<ref group="n" name="order"/> | | colspan="3" style="text-indent:2em" | 50(60)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/200Fr-1.pdf 2014] | 190(120)&nbsp;ms | α | ¹⁹⁶At | 10−# | |-id=Francium-200m2 | style="text-indent:1em" | ^200m2Fr | | colspan="3" style="text-indent:2em" | 150(50)#&nbsp;keV | style="text-align:center" | (2014)<ref group="n"> Isomer had only been suggested, not included in discovery database </ref> | 790(360)&nbsp;ns | | | | |-id=Francium-201 | ²⁰¹Fr | | style="text-align:right" | 87 | style="text-align:right" | 114 | 201.003852(10) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/201.pdf 1980] | 62.8(19)&nbsp;ms | α | ¹⁹⁷At | 9/2− | |-id=Francium-201m1 | style="text-indent:1em" | ^201m1Fr | | colspan="3" style="text-indent:2em" | 129(10)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/201Fr-1.pdf 2005] | 24(6)&nbsp;ms | α | ¹⁹⁷At | 1/2+ | |-id=Francium-201m2 | style="text-indent:1em" | ^201m2Fr | | colspan="3" style="text-indent:2em" | 289.5(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/201Fr-2.pdf 2014] | 720(40)&nbsp;ns | IT | ²⁰¹Fr | 13/2+ | |-id=Francium-202 | ²⁰²Fr | | style="text-align:right" | 87 | style="text-align:right" | 115 | 202.003330(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/202.pdf 1980] | 372(12)&nbsp;ms | α | ¹⁹⁸At | 3+ | |-id=Francium-202m | rowspan=2 style="text-indent:1em" | ^202mFr | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 257(6)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/202Fr-1.pdf 1992] | rowspan=2|286(13)&nbsp;ms | α | ¹⁹⁸At | rowspan=2|10− | rowspan=2| |- | IT (?%) | ²⁰²Fr |-id=Francium-203 | ²⁰³Fr | | style="text-align:right" | 87 | style="text-align:right" | 116 | 203.000941(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/203.pdf 1967] | 550(10)&nbsp;ms | α | ¹⁹⁹At | 9/2− | |-id=Francium-203m1 | rowspan=2 style="text-indent:1em" | ^203m1Fr | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 361(6)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/203Fr-1.pdf 2013] | rowspan=2|43(4)&nbsp;ms | IT (80%) | ²⁰³Fr | rowspan=2|1/2+ | rowspan=2| |- | α (20%) | ¹⁹⁹At |-id=Francium-203m2 | style="text-indent:1em" | ^203m2Fr | | colspan="3" style="text-indent:2em" | 426.0(10)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/203Fr-2.pdf 2013] | 370(50)&nbsp;ns | IT | ²⁰³Fr | 13/2+ | |-id=Francium-204 | rowspan=2|²⁰⁴Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 117 | rowspan=2|204.000652(26) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/204.pdf 1964] | rowspan=2|1.75(26)&nbsp;s | α (96%) | ²⁰⁰At | rowspan=2|3+ | rowspan=2| |- | β⁺ (4%) | ²⁰⁴Rn |-id=Francium-204m1 | rowspan=2 style="text-indent:1em" | ^204m1Fr | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 50(4)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/204Fr-1.pdf 1967] | rowspan=2|2.41(19)&nbsp;s | α (90%) | ²⁰⁰At | rowspan=2|7+ | rowspan=2| |- | β⁺ (10%) | ²⁰⁴Rn |-id=Francium-204m2 | rowspan=2 style="text-indent:1em" | ^204m2Fr | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 326(4)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/204Fr-2.pdf 1992] | rowspan=2|1.65(15)&nbsp;s | α (53%) | ²⁰⁰At | rowspan=2|10− | rowspan=2| |- | IT (47%) | ²⁰⁴Fr |-id=Francium-205 | rowspan=2|²⁰⁵Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 118 | rowspan=2|204.998594(8) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/205.pdf 1964] | rowspan=2|3.90(7)&nbsp;s | α (98.5%) | ²⁰¹At | rowspan=2|9/2− | rowspan=2| |- | β⁺ (1.5%) | ²⁰⁵Rn |-id=Francium-205m1 | style="text-indent:1em" | ^205m1Fr | | colspan="3" style="text-indent:2em" | 544.0(10)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/205Fr-2.pdf 2012] | 80(20)&nbsp;ns | IT | ²⁰⁵Fr | 13/2+ | |-id=Francium-205m2 | style="text-indent:1em" | ^205m2Fr | | colspan="3" style="text-indent:2em" | 609(6)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/205Fr-1.pdf 2012] | 1.15(4)&nbsp;ms | IT | ²⁰³Fr | (1/2+) | |-id=Francium-206 | rowspan=2|²⁰⁶Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 119 | rowspan=2|205.998661(30) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/206.pdf 1964] | rowspan=2|~16&nbsp;s | α (88.4%) | ²⁰²At | rowspan=2|3+ | rowspan=2| |- | β⁺ (11.6%) | ²⁰⁶Rn |-id=Francium-206m1 | rowspan=3 style="text-indent:1em" | ^206m1Fr | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 200(40)&nbsp;keV | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/206Fr-1.pdf 1981] | rowspan=3|~16&nbsp;s | α (84.7%) | ²⁰²At | rowspan=3|7+ | rowspan=3| |- | β⁺ (?%) | ²⁰⁶Rn |- | IT (?%) | ²⁰⁶Fr |-id=Francium-206m2 | rowspan=2 style="text-indent:1em" | ^206m2Fr | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 730(40)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/206Fr-1.pdf 1981] | rowspan=2|700(100)&nbsp;ms | IT (87%) | ²⁰⁶Fr | rowspan=2|10− | rowspan=2| |- | α (13%) | ²⁰²At |-id=Francium-207 | rowspan=2|²⁰⁷Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 120 | rowspan=2|206.996941(19) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/207.pdf 1964] | rowspan=2|14.8(1)&nbsp;s | α (95%) | ²⁰³At | rowspan=2|9/2− | rowspan=2| |- | β⁺ (5%) | ²⁰⁷Rn |-id=Francium-208 | rowspan=2|²⁰⁸Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 121 | rowspan=2|207.997139(13) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/208.pdf 1964] | rowspan=2|59.1(3)&nbsp;s | α (89%) | ²⁰⁴At | rowspan=2|7+ | rowspan=2| |- | β⁺ (11%) | ²⁰⁸Rn |-id=Francium-208m | style="text-indent:1em" | ^208mFr | | colspan="3" style="text-indent:2em" | 826.3(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/208Fr-1.pdf 2009] | 432(11)&nbsp;ns | IT | ²⁰⁸Fr | 10− | |-id=Francium-209 | rowspan=2|²⁰⁹Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 122 | rowspan=2|208.995940(12) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/209.pdf 1964] | rowspan=2|50.5(7)&nbsp;s | α (89%) | ²⁰⁵At | rowspan=2|9/2− | rowspan=2| |- | β⁺ (11%) | ²⁰⁹Rn |-id=Francium-209m | style="text-indent:1em" | ^209mFr | | colspan="3" style="text-indent:2em" | 4659.8(7)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/209Fr-1.pdf 2006] | 420(18)&nbsp;ns | IT | ²⁰⁹Fr | 45/2− | |-id=Francium-210 | rowspan=2|²¹⁰Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 123 | rowspan=2|209.996411(14) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/210.pdf 1964] | rowspan=2|3.18(6)&nbsp;min | α (71%) | ²⁰⁶At | rowspan=2|6+ | rowspan=2| |- | β⁺ (29%) | ²¹⁰Rn |-id=Francium-210m | style="text-indent:1em" | ^210mFr | | colspan="3" style="text-indent:2em" | 4417.2(10)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/210Fr-1.pdf 2016] | 475(6)&nbsp;ns | IT | ²¹⁰Fr | (23)+ | |-id=Francium-211 | rowspan=2|²¹¹Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 124 | rowspan=2|210.995555(13) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/211.pdf 1964] | rowspan=2|3.10(2)&nbsp;min | α (87%) | ²⁰⁷At | rowspan=2|9/2− | rowspan=2| |- | β⁺ (13%) | ²¹¹Rn |-id=Francium-211m1 | style="text-indent:1em" | ^211m1Fr | | colspan="3" style="text-indent:2em" | 2423.16(24)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/211Fr-1.pdf 1986] | 146(14)&nbsp;ns | IT | ²¹¹Fr | 29/2+ | |-id=Francium-211m2 | style="text-indent:1em" | ^211m2Fr | | colspan="3" style="text-indent:2em" | 4657.3(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/211Fr-2.pdf 1986] | 124.5(12)&nbsp;ns | IT | ²¹¹Fr | 45/2− | |-id=Francium-212 | rowspan=2|²¹²Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 125 | rowspan=2|211.996225(9) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/212.pdf 1950] | rowspan=2|20.0(6)&nbsp;min | β⁺ (57%) | ²¹²Rn | rowspan=2|5+ | rowspan=2| |- | α (43%) | ²⁰⁸At |-id=Francium-212m1 | style="text-indent:1em" | ^212m1Fr | | colspan="3" style="text-indent:2em" | 1551.4(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/212Fr-3.pdf 1990] | 31.9(7)&nbsp;μs | IT | ²¹²Fr | 11+ | |-id=Francium-212m2 | style="text-indent:1em" | ^212m2Fr | | colspan="3" style="text-indent:2em" | 2492.2(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/212Fr-1.pdf 1977] | 604(28)&nbsp;ns | IT | ²¹²Fr | 15− | |-id=Francium-212m3 | style="text-indent:1em" | ^212m3Fr | | colspan="3" style="text-indent:2em" | 5854.7(6)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/212Fr-2.pdf 1986] | 312(21)&nbsp;ns | IT | ²¹²Fr | 27− | |-id=Francium-212m4 | style="text-indent:1em" | ^212m4Fr | | colspan="3" style="text-indent:2em" | 8533.4(11)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/212Fr-4.pdf 1990] | 23.6(21)&nbsp;μs | IT | ²¹²Fr | 34+# | |-id=Francium-213 | rowspan=2|²¹³Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 126 | rowspan=2|212.996184(5) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/213.pdf 1964] | rowspan=2|34.14(6)&nbsp;s | α (99.44%) | ²⁰⁹At | rowspan=2|9/2− | rowspan=2| |- | β⁺ (0.56%) | ²¹³Rn |-id=Francium-213m1 | style="text-indent:1em" | ^213m1Fr | | colspan="3" style="text-indent:2em" | 1590.41(18)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/213Fr-1.pdf 1976] | 505(14)&nbsp;ns | IT | ²¹³Fr | 21/2− | |-id=Francium-213m2 | style="text-indent:1em" | ^213m2Fr | | colspan="3" style="text-indent:2em" | 2537.62(23)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/213Fr-2.pdf 1976] | 238(6)&nbsp;ns | IT | ²¹³Fr | 29/2+ | |-id=Francium-213m3 | style="text-indent:1em" | ^213m3Fr | | colspan="3" style="text-indent:2em" | 8094.8(7)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/213Fr-3.pdf 1989] | 3.1(2)&nbsp;μs | IT | ²¹³Fr | (65/2−) | |-id=Francium-214 | ²¹⁴Fr | | style="text-align:right" | 87 | style="text-align:right" | 127 | 213.998971(9) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/214.pdf 1966] | 5.51(13)&nbsp;ms | α | ²¹⁰At | (1−) | |-id=Francium-214m1 | style="text-indent:1em" | ^214m1Fr | | colspan="3" style="text-indent:2em" | 121(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/214Fr-1.pdf 1968] | 3.35(5)&nbsp;ms | α | ²¹⁰At | (8−) | |-id=Francium-214m2 | style="text-indent:1em" | ^214m2Fr | | colspan="3" style="text-indent:2em" | 638(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/214Fr-3.pdf 1994] | 103(4)&nbsp;ns | IT | ²¹⁴Fr | (11+) | |-id=Francium-214m3 | style="text-indent:1em" | ^214m3Fr | | colspan="3" style="text-indent:2em" | 6577(100)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/214Fr-2.pdf 1994] | 108(7)&nbsp;ns | IT | ²¹⁴Fr | (33+) | |-id=Francium-215 | ²¹⁵Fr | | style="text-align:right" | 87 | style="text-align:right" | 128 | 215.000342(8) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/215.pdf 1970] | 90(4)&nbsp;ns | α | ²¹¹At | 9/2− | |-id=Francium-216 |²¹⁶Fr | | style="text-align:right" | 87 | style="text-align:right" | 129 | 216.003190(4) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/216.pdf 1970] | 700(20)&nbsp;ns | α | ²¹²At | (1−) | |-id=Francium-216m | style="text-indent:1em" | ^216mFr | | colspan="3" style="text-indent:2em" | 219(6)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/216Fr-1.pdf 2007] | 850(30)&nbsp;ns | α | ^212m1At<ref>{{cite web|url=https://www.nndc.bnl.gov/ensnds/212/At/a_decay_850_ns.pdf|title=²¹⁶Fr α decay (850)|publisher=NNDC Chart of Nuclides}}</ref> | (9−) | |-id=Francium-217 | ²¹⁷Fr | | style="text-align:right" | 87 | style="text-align:right" | 130 | 217.004632(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/217.pdf 1968] | 22(5)&nbsp;μs | α | ²¹³At | 9/2− | |-id=Francium-218 | ²¹⁸Fr | | style="text-align:right" | 87 | style="text-align:right" | 131 | 218.007579(5) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/218.pdf 1949] | 1.4(5)&nbsp;ms | α | ²¹⁴At | 1− | |-id=Francium-218m |style="text-indent:1em" | ^218mFr | | colspan="3" style="text-indent:2em" | 87(4)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/87/218Fr-1.pdf 1982] | 21.9(5)&nbsp;ms | α | ²¹⁴At | (8−) | |-id=Francium-219 | ²¹⁹Fr | | style="text-align:right" | 87 | style="text-align:right" | 132 | 219.009251(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/219.pdf 1948] | 22.5(17)&nbsp;ms | α | ²¹⁵At | 9/2− | |-id=Francium-220 | rowspan=2|²²⁰Fr | rowspan=2| | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 133 | rowspan=2|220.012327(4) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/220.pdf 1948] | rowspan=2|27.4(3)&nbsp;s | α (99.65%) | ²¹⁶At | rowspan=2|1+ | rowspan=2| |- | β⁻ (0.35%) | ²²⁰Ra |-id=Francium-221 | rowspan=3|²²¹Fr | rowspan=3| | rowspan=3 style="text-align:right" | 87 | rowspan=3 style="text-align:right" | 134 | rowspan=3|221.014254(5) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/221.pdf 1947] | rowspan=3|4.801(5)&nbsp;min | α | ²¹⁷At | rowspan=3|5/2− | rowspan=3|Trace<ref group=n>Intermediate decay product of ²³⁷Np</ref> |- | β⁻ (0.0048%) | ²²¹Ra |- | CD (8.8×10⁻¹¹%)<ref group="n">The nuclide with the lowest atomic number known to undergo cluster decay</ref> | ²⁰⁷Tl<br>¹⁴C |-id=Francium-222 | ²²²Fr | | style="text-align:right" | 87 | style="text-align:right" | 135 | 222.017583(8) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/222.pdf 1975] | 14.2(3)&nbsp;min | β⁻{{refn|group=n|Theoretically capable of α decay to ²¹⁸At with a partial half-life of ~1 d (branching ratio ~1%).<ref>{{Citation |last1=Hyde |first1=E. K. |last2=Ghiorso |first2=A. |title=Preparation of a New Isotope of Francium - Fr²²² |date=4 February 1950 |url=https://escholarship.org/uc/item/6xx699r2 |location=California Univ., Berkeley (USA) |publisher=Radiation Laboratory}}</ref>}} | ²²²Ra | 2− | |-id=Francium-223 | rowspan=2|²²³Fr | rowspan=2|Actinium K | rowspan=2 style="text-align:right" | 87 | rowspan=2 style="text-align:right" | 136 | rowspan=2|223.0197342(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/223.pdf 1939] | rowspan=2|22.00(7)&nbsp;min | β⁻ | ²²³Ra | rowspan=2|3/2− | rowspan=2|Trace<ref group="n">Intermediate decay product of ²³⁵U</ref> |- | α (0.006%) | ²¹⁹At |-id=Francium-224 | ²²⁴Fr | | style="text-align:right" | 87 | style="text-align:right" | 137 | 224.023348(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/224.pdf 1969] | 3.33(10)&nbsp;min | β⁻ | ²²⁴Ra | 1− | |-id=Francium-225 | ²²⁵Fr | | style="text-align:right" | 87 | style="text-align:right" | 138 | 225.025572(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/225.pdf 1969] | 3.95(14)&nbsp;min | β⁻ | ²²⁵Ra | 3/2− | |-id=Francium-226 | ²²⁶Fr | | style="text-align:right" | 87 | style="text-align:right" | 139 | 226.029545(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/226.pdf 1969] | 48.5(7)&nbsp;s | β⁻ | ²²⁶Ra | 1− | |-id=Francium-227 | ²²⁷Fr | | style="text-align:right" | 87 | style="text-align:right" | 140 | 227.031865(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/227.pdf 1972] | 2.47(3)&nbsp;min | β⁻ | ²²⁷Ra | 1/2+ | |-id=Francium-228 | ²²⁸Fr | | style="text-align:right" | 87 | style="text-align:right" | 141 | 228.035839(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/228.pdf 1972] | 38(1)&nbsp;s | β⁻ | ²²⁸Ra | 2− | |-id=Francium-228m |style="text-indent:1em" | ^228mFr | | colspan="3" style="text-indent:2em" | 1004(30)&nbsp;keV | style="text-align:center" | (2008)<ref group="n">Only published in a conference proceeding and not a refereed journal</ref> | 180(110)&nbsp;s | | | | |-id=Francium-229 | ²²⁹Fr | | style="text-align:right" | 87 | style="text-align:right" | 142 | 229.038291(5) | style="text-align:center" |[https://www.nndc.bnl.gov/discovery/abstracts/87/229.pdf 1975] | 50.2(4)&nbsp;s | β⁻ | ²²⁹Ra | (1/2+) | |-id=Francium-230 | ²³⁰Fr | | style="text-align:right" | 87 | style="text-align:right" | 143 | 230.042391(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/230.pdf 1987] | 19.1(5)&nbsp;s | β⁻ | ²³⁰Ra | 2+# | |-id=Francium-231 | ²³¹Fr | | style="text-align:right" | 87 | style="text-align:right" | 144 | 231.045175(8) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/231.pdf 1985] | 17.6(6)&nbsp;s | β⁻ | ²³¹Ra | (1/2+) | |-id=Francium-232 | ²³²Fr | | style="text-align:right" | 87 | style="text-align:right" | 145 | 232.049461(15) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/232.pdf 1990] | 5.5(6)&nbsp;s | β⁻ | ²³²Ra | (5) | |-id=Francium-233 | ²³³Fr | | style="text-align:right" | 87 | style="text-align:right" | 146 | 233.052518(21) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/87/233.pdf 2010] | 900(100)&nbsp;ms | β⁻ | ²³³Ra | 1/2+# | {{Isotopes table/footer}}

== References == {{Reflist}}

* Half-life, spin, and isomer data selected from the following sources. **{{NUBASE 2003}} **{{NNDC}} **{{CRC85|chapter=11}}

{{Navbox element isotopes}}

Category:Isotopes of francium Francium