Isotopes of praseodymium

Naturally occurring praseodymium (59Pr) is composed of one stable isotope, 141Pr. Thirty-eight radioisotopes have been characterized with the most stable being 143Pr, with a half-life of 13.57 days and 142Pr, with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.985 hours and the majority of these have half-lives that are less than 33 seconds. This element also has 15 meta states with the most stable being 138mPr (t1/2 2.12 hours), 142mPr (t1/2 14.6 minutes) and 134mPr (t1/2 11 minutes).

The isotopes of praseodymium range in atomic weight from 120.955 u (121Pr) to 158.955 u (159Pr). The primary decay mode before the stable isotope, 141Pr, is electron capture and the mode after is beta decay. The primary decay products before 141Pr are element 58 (cerium) isotopes and the primary products after are element 60 (neodymium) isotopes.

List of isotopes

 * rowspan=3|121Pr
 * rowspan=3 style="text-align:right" | 59
 * rowspan=3 style="text-align:right" | 62
 * rowspan=3|120.95536(75)#
 * rowspan=3|600(300) ms
 * p
 * 120Ce
 * rowspan=3|(3/2−)
 * rowspan=3|
 * β+ (rare)
 * 121Ce
 * β+, p (rare)
 * 120La
 * 122Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 63
 * 121.95181(54)#
 * 500# ms
 * β+
 * 122Ce
 * 123Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 64
 * 122.94596(64)#
 * 800# ms
 * β+
 * 123Ce
 * 3/2+#
 * rowspan=2|124Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 65
 * rowspan=2|123.94296(64)#
 * rowspan=2|1.2(2) s
 * β+
 * 124Ce
 * rowspan=2|
 * rowspan=2|
 * β+, p (rare)
 * 123La
 * rowspan=2|125Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 66
 * rowspan=2|124.93783(43)#
 * rowspan=2|3.3(7) s
 * β+
 * 125Ce
 * rowspan=2|3/2+#
 * rowspan=2|
 * β+, p (rare)
 * 124La
 * rowspan=2|126Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 67
 * rowspan=2|125.93531(21)#
 * rowspan=2|3.12(18) s
 * β+
 * 126Ce
 * rowspan=2|(4, 5, 6)
 * rowspan=2|
 * β+, p (rare)
 * 125La
 * 127Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 68
 * 126.93083(21)#
 * 4.2(3) s
 * β+
 * 127Ce
 * 3/2+#
 * style="text-indent:1em" | 127mPr
 * colspan="3" style="text-indent:2em" | 600(200)# keV
 * 50# ms
 * 11/2−
 * rowspan=2|128Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 69
 * rowspan=2|127.92879(3)
 * rowspan=2|2.84(9) s
 * β+
 * 128Ce
 * rowspan=2|(3+)
 * rowspan=2|
 * β+, p (rare)
 * 127La
 * 129Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 70
 * 128.92510(3)
 * 32(3) s
 * β+
 * 129Ce
 * (11/2−)
 * style="text-indent:1em" | 129mPr
 * colspan="3" style="text-indent:2em" | 382.7(5) keV
 * 1# ms
 * β+
 * 129Ce
 * (11/2−)
 * 130Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 71
 * 129.92359(7)
 * 40.0(4) s
 * β+
 * 130Ce
 * (6, 7)(+#)
 * style="text-indent:1em" | 130mPr
 * colspan="3" style="text-indent:2em" | 100(100)# keV
 * 10# s
 * 2+#
 * 131Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 72
 * 130.92026(6)
 * 1.50(3) min
 * β+
 * 131Ce
 * (3/2+)
 * rowspan=2 style="text-indent:1em" | 131mPr
 * rowspan=2 colspan="3" style="text-indent:2em" | 152.4(2) keV
 * rowspan=2|5.7(2) s
 * IT (96.4%)
 * 131Pr
 * rowspan=2|(11/2−)
 * rowspan=2|
 * β+ (3.59%)
 * 131Ce
 * 132Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 73
 * 131.91926(6)
 * 1.49(11) min
 * β+
 * 132Ce
 * (2+)
 * style="text-indent:1em" | 132mPr
 * colspan="3" style="text-indent:2em" | 0(100)# keV
 * 20# s
 * β+
 * 132Ce
 * (5+)
 * 133Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 74
 * 132.916331(13)
 * 6.5(3) min
 * β+
 * 133Ce
 * (3/2+)
 * style="text-indent:1em" | 133mPr
 * colspan="3" style="text-indent:2em" | 192.05(14) keV
 * 1.1(2) μs
 * (11/2−)
 * 134Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 75
 * 133.91571(4)
 * 17(2) min
 * β+
 * 134Ce
 * (5−)
 * style="text-indent:1em" | 134mPr
 * colspan="3" style="text-indent:2em" | 0(100)# keV
 * ~11 min
 * β+
 * 134Ce
 * 2−
 * 135Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 76
 * 134.913112(13)
 * 24(2) min
 * β+
 * 135Ce
 * 3/2(+)
 * style="text-indent:1em" | 135mPr
 * colspan="3" style="text-indent:2em" | 358.06(6) keV
 * 105(10) μs
 * (11/2−)
 * 136Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 77
 * 135.912692(13)
 * 13.1(1) min
 * β+
 * 136Ce
 * 2+
 * 137Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 78
 * 136.910705(13)
 * 1.28(3) h
 * β+
 * 137Ce
 * 5/2+
 * style="text-indent:1em" | 137mPr
 * colspan="3" style="text-indent:2em" | 561.22(23) keV
 * 2.66(7) μs
 * 11/2−
 * 138Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 79
 * 137.910755(15)
 * 1.45(5) min
 * β+
 * 138Ce
 * 1+
 * style="text-indent:1em" | 138mPr
 * colspan="3" style="text-indent:2em" | 348(23) keV
 * 2.12(4) h
 * β+
 * 138Ce
 * 7−
 * 139Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 80
 * 138.908938(8)
 * 4.41(4) h
 * β+
 * 139Ce
 * 5/2+
 * rowspan=2|140Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 81
 * rowspan=2|139.909076(7)
 * rowspan=2|3.39(1) min
 * EC (51.3(22)%)
 * rowspan=2|140Ce
 * rowspan=2|1+
 * rowspan=2|
 * β+ (48.7(22)%)
 * style="text-indent:1em" | 140m1Pr
 * colspan="3" style="text-indent:2em" | 127.5(3) keV
 * 0.35(2) μs
 * 5+
 * style="text-indent:1em" | 140m2Pr
 * colspan="3" style="text-indent:2em" | 763.3(7) keV
 * 3.05(20) μs
 * (8)−
 * 141Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 82
 * 140.9076528(26)
 * colspan=3 align=center|Stable
 * 5/2+
 * 1.0000
 * rowspan=2|142Pr
 * rowspan=2 style="text-align:right" | 59
 * rowspan=2 style="text-align:right" | 83
 * rowspan=2|141.9100448(26)
 * rowspan=2|19.12(4) h
 * β− (99.98%)
 * 142Nd
 * rowspan=2|2−
 * rowspan=2|
 * EC (.0164%)
 * 142Ce
 * style="text-indent:1em" | 142mPr
 * colspan="3" style="text-indent:2em" | 3.694(3) keV
 * 14.6(5) min
 * IT
 * 142Pr
 * 5−
 * 143Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 84
 * 142.9108169(28)
 * 13.57(2) d
 * β−
 * 143Nd
 * 7/2+
 * 144Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 85
 * 143.913305(4)
 * 17.28(5) min
 * β−
 * 144Nd
 * 0−
 * rowspan=2 style="text-indent:1em" | 144mPr
 * rowspan=2 colspan="3" style="text-indent:2em" | 59.03(3) keV
 * rowspan=2|7.2(3) min
 * IT (99.93%)
 * 144Pr
 * rowspan=2|3−
 * rowspan=2|
 * β− (.07%)
 * 144Nd
 * 145Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 86
 * 144.914512(8)
 * 5.984(10) h
 * β−
 * 145Nd
 * 7/2+
 * 146Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 87
 * 145.91764(7)
 * 24.15(18) min
 * β−
 * 146Nd
 * (2)−
 * 147Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 88
 * 146.918996(25)
 * 13.4(4) min
 * β−
 * 147Nd
 * (3/2+)
 * 148Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 89
 * 147.922135(28)
 * 2.29(2) min
 * β−
 * 148Nd
 * 1−
 * style="text-indent:1em" | 148mPr
 * colspan="3" style="text-indent:2em" | 50(30)# keV
 * 2.01(7) min
 * β−
 * 148Nd
 * (4)
 * 149Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 90
 * 148.92372(9)
 * 2.26(7) min
 * β−
 * 149Nd
 * (5/2+)
 * 150Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 91
 * 149.926673(28)
 * 6.19(16) s
 * β−
 * 150Nd
 * (1)−
 * 151Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 92
 * 150.928319(25)
 * 18.90(7) s
 * β−
 * 151Nd
 * (3/2)(−#)
 * 152Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 93
 * 151.93150(13)
 * 3.63(12) s
 * β−
 * 152Nd
 * 4+
 * 153Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 94
 * 152.93384(11)
 * 4.28(11) s
 * β−
 * 153Nd
 * 5/2−#
 * 154Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 95
 * 153.93752(16)
 * 2.3(1) s
 * β−
 * 154Nd
 * (3+, 2+)
 * 155Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 96
 * 154.94012(32)#
 * 1# s [>300 ns]
 * β−
 * 155Nd
 * 5/2−#
 * 156Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 97
 * 155.94427(43)#
 * 500# ms [>300 ns]
 * β−
 * 156Nd
 * 157Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 98
 * 156.94743(43)#
 * 300# ms
 * β−
 * 157Nd
 * 5/2−#
 * 158Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 99
 * 157.95198(64)#
 * 200# ms
 * β−
 * 158Nd
 * 159Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 100
 * 158.95550(75)#
 * 100# ms
 * β−
 * 159Nd
 * 5/2−#
 * style="text-align:right" | 89
 * 147.922135(28)
 * 2.29(2) min
 * β−
 * 148Nd
 * 1−
 * style="text-indent:1em" | 148mPr
 * colspan="3" style="text-indent:2em" | 50(30)# keV
 * 2.01(7) min
 * β−
 * 148Nd
 * (4)
 * 149Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 90
 * 148.92372(9)
 * 2.26(7) min
 * β−
 * 149Nd
 * (5/2+)
 * 150Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 91
 * 149.926673(28)
 * 6.19(16) s
 * β−
 * 150Nd
 * (1)−
 * 151Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 92
 * 150.928319(25)
 * 18.90(7) s
 * β−
 * 151Nd
 * (3/2)(−#)
 * 152Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 93
 * 151.93150(13)
 * 3.63(12) s
 * β−
 * 152Nd
 * 4+
 * 153Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 94
 * 152.93384(11)
 * 4.28(11) s
 * β−
 * 153Nd
 * 5/2−#
 * 154Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 95
 * 153.93752(16)
 * 2.3(1) s
 * β−
 * 154Nd
 * (3+, 2+)
 * 155Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 96
 * 154.94012(32)#
 * 1# s [>300 ns]
 * β−
 * 155Nd
 * 5/2−#
 * 156Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 97
 * 155.94427(43)#
 * 500# ms [>300 ns]
 * β−
 * 156Nd
 * 157Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 98
 * 156.94743(43)#
 * 300# ms
 * β−
 * 157Nd
 * 5/2−#
 * 158Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 99
 * 157.95198(64)#
 * 200# ms
 * β−
 * 158Nd
 * 159Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 100
 * 158.95550(75)#
 * 100# ms
 * β−
 * 159Nd
 * 5/2−#
 * style="text-align:right" | 98
 * 156.94743(43)#
 * 300# ms
 * β−
 * 157Nd
 * 5/2−#
 * 158Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 99
 * 157.95198(64)#
 * 200# ms
 * β−
 * 158Nd
 * 159Pr
 * style="text-align:right" | 59
 * style="text-align:right" | 100
 * 158.95550(75)#
 * 100# ms
 * β−
 * 159Nd
 * 5/2−#
 * 158.95550(75)#
 * 100# ms
 * β−
 * 159Nd
 * 5/2−#