Isotopes of antimony

Antimony (51Sb) occurs in two stable isotopes, 121Sb and 123Sb. There are 35 artificial radioactive isotopes, the longest-lived of which are 125Sb, with a half-life of 2.75856 years; 124Sb, with a half-life of 60.2 days; and 126Sb, with a half-life of 12.35 days. All other isotopes have half-lives less than 4 days, most less than an hour.

There are also many isomers, the longest-lived of which is 120m1Sb with a half-life of 5.76 days.

With the exception of beryllium, antimony is the lightest element observed to have isotopes capable of undergoing alpha decay, with the isotope 104Sb being seen to undergo this mode of decay. Some lighter elements, namely those in the vicinity of 8Be, have isotopes with delayed alpha emission (following proton or beta emission) as a rare branch.

List of isotopes

 * 103Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 52
 * 102.93969(32)#
 * 100# ms [>1.5 μs]
 * β+
 * 103Sn
 * 5/2+#
 * rowspan=4|104Sb
 * rowspan=4 style="text-align:right" | 51
 * rowspan=4 style="text-align:right" | 53
 * rowspan=4|103.93647(39)#
 * rowspan=4|0.47(13) s [0.44(+15−11) s]
 * β+ (86%)
 * 104Sn
 * rowspan=4|
 * rowspan=4|
 * rowspan=4|
 * p (7%)
 * 103Sn
 * β+, p (7%)
 * 103In
 * α (<1%)
 * 100In
 * rowspan=3|105Sb
 * rowspan=3 style="text-align:right" | 51
 * rowspan=3 style="text-align:right" | 54
 * rowspan=3|104.93149(11)
 * rowspan=3|1.12(16) s
 * β+ (99%)
 * 105Sn
 * rowspan=3|(5/2+)
 * rowspan=3|
 * rowspan=3|
 * p (1%)
 * 104Sn
 * β+, p (<1%)
 * 104In
 * 106Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 55
 * 105.92879(34)#
 * 0.6(2) s
 * β+
 * 106Sn
 * (4+)
 * style="text-indent:1em" | 106mSb
 * colspan="3" style="text-indent:2em" | 1000(500)# keV
 * 220(20) ns
 * 107Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 56
 * 106.92415(32)#
 * 4.0(2) s
 * β+
 * 107Sn
 * 5/2+#
 * rowspan=2|108Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 57
 * rowspan=2|107.92216(22)#
 * rowspan=2|7.4(3) s
 * β+
 * 108Sn
 * rowspan=2|(4+)
 * rowspan=2|
 * rowspan=2|
 * β+, p (rare)
 * 107In
 * 109Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 58
 * 108.918132(20)
 * 17.3(5) s
 * β+
 * 109Sn
 * 5/2+#
 * 110Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 59
 * 109.91675(22)#
 * 23.0(4) s
 * β+
 * 110Sn
 * (4+)
 * 111Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 60
 * 110.91316(3)
 * 75(1) s
 * β+
 * 111Sn
 * (5/2+)
 * 112Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 61
 * 111.912398(19)
 * 51.4(10) s
 * β+
 * 112Sn
 * 3+
 * 113Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 62
 * 112.909372(19)
 * 6.67(7) min
 * β+
 * 113Sn
 * 5/2+
 * 114Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 63
 * 113.90927(3)
 * 3.49(3) min
 * β+
 * 114Sn
 * (3+)
 * style="text-indent:1em" | 114mSb
 * colspan="3" style="text-indent:2em" | 495.5(7) keV
 * 219(12) μs
 * (8−)
 * 115Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 64
 * 114.906598(17)
 * 32.1(3) min
 * β+
 * 115Sn
 * 5/2+
 * 116Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 65
 * 115.906794(6)
 * 15.8(8) min
 * β+
 * 116Sn
 * 3+
 * style="text-indent:1em" | 116m1Sb
 * colspan="3" style="text-indent:2em" | 93.99(5) keV
 * 194(4) ns
 * 1+
 * style="text-indent:1em" | 116m2Sb
 * colspan="3" style="text-indent:2em" | 380(40) keV
 * 60.3(6) min
 * β+
 * 116Sn
 * 8−
 * 117Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 66
 * 116.904836(10)
 * 2.80(1) h
 * β+
 * 117Sn
 * 5/2+
 * 118Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 67
 * 117.905529(4)
 * 3.6(1) min
 * β+
 * 118Sn
 * 1+
 * style="text-indent:1em" | 118m1Sb
 * colspan="3" style="text-indent:2em" | 50.814(21) keV
 * 20.6(6) μs
 * (3)+
 * style="text-indent:1em" | 118m2Sb
 * colspan="3" style="text-indent:2em" | 250(6) keV
 * 5.00(2) h
 * β+
 * 118Sn
 * 8−
 * 119Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 68
 * 118.903942(9)
 * 38.19(22) h
 * EC
 * 119Sn
 * 5/2+
 * style="text-indent:1em" | 119m1Sb
 * colspan="3" style="text-indent:2em" | 2553.6(3) keV
 * 130(3) ns
 * (19/2−)
 * style="text-indent:1em" | 119m2Sb
 * colspan="3" style="text-indent:2em" | 2852(7) keV
 * 850(90) ms
 * IT
 * 119Sb
 * 27/2+#
 * 120Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 69
 * 119.905072(8)
 * 15.89(4) min
 * β+
 * 120Sn
 * 1+
 * style="text-indent:1em" | 120m1Sb
 * colspan="3" style="text-indent:2em" | 0(100)# keV
 * 5.76(2) d
 * β+
 * 120Sn
 * 8−
 * style="text-indent:1em" | 120m2Sb
 * colspan="3" style="text-indent:2em" | 78.16(5) keV
 * 246(2) ns
 * (3+)
 * style="text-indent:1em" | 120m3Sb
 * colspan="3" style="text-indent:2em" | 2328.3(6) keV
 * 400(8) ns
 * (6)
 * 121Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 70
 * 120.9038157(24)
 * colspan=3 align=center|Stable
 * 5/2+
 * 0.5721(5)
 * rowspan=2|122Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 71
 * rowspan=2|121.9051737(24)
 * rowspan=2|2.7238(2) d
 * β− (97.59%)
 * 122Te
 * rowspan=2|2−
 * rowspan=2|
 * rowspan=2|
 * β+ (2.41%)
 * 122Sn
 * style="text-indent:1em" | 122m1Sb
 * colspan="3" style="text-indent:2em" | 61.4131(5) keV
 * 1.86(8) μs
 * 3+
 * style="text-indent:1em" | 122m2Sb
 * colspan="3" style="text-indent:2em" | 137.4726(8) keV
 * 0.53(3) ms
 * (5)+
 * style="text-indent:1em" | 122m3Sb
 * colspan="3" style="text-indent:2em" | 163.5591(17) keV
 * 4.191(3) min
 * IT
 * 122Sb
 * (8)−
 * 123Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 72
 * 122.9042140(22)
 * colspan=3 align=center|Stable
 * 7/2+
 * 0.4279(5)
 * 124Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 73
 * 123.9059357(22)
 * 60.20(3) d
 * β−
 * 124Te
 * 3−
 * rowspan=2 style="text-indent:1em" | 124m1Sb
 * rowspan=2 colspan="3" style="text-indent:2em" | 10.8627(8) keV
 * rowspan=2|93(5) s
 * IT (75%)
 * 124Sb
 * rowspan=2|5+
 * rowspan=2|
 * rowspan=2|
 * β− (25%)
 * 124Te
 * style="text-indent:1em" | 124m2Sb
 * colspan="3" style="text-indent:2em" | 36.8440(14) keV
 * 20.2(2) min
 * (8)−
 * style="text-indent:1em" | 124m3Sb
 * colspan="3" style="text-indent:2em" | 40.8038(7) keV
 * 3.2(3) μs
 * (3+, 4+)
 * 125Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 74
 * 124.9052538(28)
 * 2.75856(25) y
 * β−
 * 125mTe
 * 7/2+
 * 126Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 75
 * 125.90725(3)
 * 12.35(6) d
 * β−
 * 126Te
 * (8−)
 * rowspan=2 style="text-indent:1em" | 126m1Sb
 * rowspan=2 colspan="3" style="text-indent:2em" | 17.7(3) keV
 * rowspan=2|19.15(8) min
 * β− (86%)
 * 126Te
 * rowspan=2|(5+)
 * rowspan=2|
 * rowspan=2|
 * IT (14%)
 * 126Sb
 * style="text-indent:1em" | 126m2Sb
 * colspan="3" style="text-indent:2em" | 40.4(3) keV
 * ~11 s
 * IT
 * 126m1Sb
 * (3−)
 * style="text-indent:1em" | 126m3Sb
 * colspan="3" style="text-indent:2em" | 104.6(3) keV
 * 553(5) ns
 * (3+)
 * 127Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 76
 * 126.906924(6)
 * 3.85(5) d
 * β−
 * 127mTe
 * 7/2+
 * 128Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 77
 * 127.909169(27)
 * 9.01(4) h
 * β−
 * 128Te
 * 8−
 * rowspan=2 style="text-indent:1em" | 128mSb
 * rowspan=2 colspan="3" style="text-indent:2em" | 10(7) keV
 * rowspan=2|10.4(2) min
 * β− (96.4%)
 * 128Te
 * rowspan=2|5+
 * rowspan=2|
 * rowspan=2|
 * IT (3.6%)
 * 128Sb
 * 129Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 78
 * 128.909148(23)
 * 4.40(1) h
 * β−
 * 129mTe
 * 7/2+
 * rowspan=2 style="text-indent:1em" | 129m1Sb
 * rowspan=2 colspan="3" style="text-indent:2em" | 1851.05(10) keV
 * rowspan=2|17.7(1) min
 * β− (85%)
 * 129Te
 * rowspan=2|(19/2−)
 * rowspan=2|
 * rowspan=2|
 * IT (15%)
 * 129Sb
 * style="text-indent:1em" | 129m2Sb
 * colspan="3" style="text-indent:2em" | 1860.90(10) keV
 * >2 μs
 * (15/2−)
 * style="text-indent:1em" | 129m3Sb
 * colspan="3" style="text-indent:2em" | 2138.9(5) keV
 * 1.1(1) μs
 * (23/2+)
 * 130Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 79
 * 129.911656(18)
 * 39.5(8) min
 * β−
 * 130Te
 * (8−)#
 * style="text-indent:1em" | 130mSb
 * colspan="3" style="text-indent:2em" | 4.80(20) keV
 * 6.3(2) min
 * β−
 * 130Te
 * (4, 5)+
 * 131Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 80
 * 130.911982(22)
 * 23.03(4) min
 * β−
 * 131mTe
 * (7/2+)
 * 132Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 81
 * 131.914467(15)
 * 2.79(5) min
 * β−
 * 132Te
 * (4+)
 * style="text-indent:1em" | 132m1Sb
 * colspan="3" style="text-indent:2em" | 200(30) keV
 * 4.15(5) min
 * β−
 * 132Te
 * (8−)
 * style="text-indent:1em" | 132m2Sb
 * colspan="3" style="text-indent:2em" | 254.5(3) keV
 * 102(4) ns
 * (6−)
 * 133Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 82
 * 132.915252(27)
 * 2.5(1) min
 * β−
 * 133mTe
 * (7/2+)
 * 134Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 83
 * 133.92038(5)
 * 0.78(6) s
 * β−
 * 134Te
 * (0-)
 * rowspan=2 style="text-indent:1em" | 134mSb
 * rowspan=2 colspan="3" style="text-indent:2em" | 80(110) keV
 * rowspan=2|10.07(5) s
 * β− (99.9%)
 * 134Te
 * rowspan=2|(7−)
 * rowspan=2|
 * rowspan=2|
 * β−, n (.091%)
 * 133Te
 * rowspan=2|135Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 84
 * rowspan=2|134.92517(11)
 * rowspan=2|1.68(2) s
 * β− (82.4%)
 * 135Te
 * rowspan=2|(7/2+)
 * rowspan=2|
 * rowspan=2|
 * β−, n (17.6%)
 * 134Te
 * rowspan=2|136Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 85
 * rowspan=2|135.93035(32)#
 * rowspan=2|0.923(14) s
 * β− (83%)
 * 136Te
 * rowspan=2|1−#
 * rowspan=2|
 * rowspan=2|
 * β−, n (17%)
 * 135Te
 * style="text-indent:1em" | 136mSb
 * colspan="3" style="text-indent:2em" | 173(3) keV
 * 570(50) ns
 * 6−#
 * rowspan=2|137Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 86
 * rowspan=2|136.93531(43)#
 * rowspan=2|450(50) ms
 * β−
 * 137Te
 * rowspan=2|7/2+#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 136Te
 * rowspan=2|138Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 87
 * rowspan=2|137.94079(32)#
 * rowspan=2|500# ms [>300 ns]
 * β−
 * 138Te
 * rowspan=2|2−#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 137Te
 * 139Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 88
 * 138.94598(54)#
 * 300# ms [>300 ns]
 * β−
 * 139Te
 * 7/2+#
 * β− (96.4%)
 * 128Te
 * rowspan=2|5+
 * rowspan=2|
 * rowspan=2|
 * IT (3.6%)
 * 128Sb
 * 129Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 78
 * 128.909148(23)
 * 4.40(1) h
 * β−
 * 129mTe
 * 7/2+
 * rowspan=2 style="text-indent:1em" | 129m1Sb
 * rowspan=2 colspan="3" style="text-indent:2em" | 1851.05(10) keV
 * rowspan=2|17.7(1) min
 * β− (85%)
 * 129Te
 * rowspan=2|(19/2−)
 * rowspan=2|
 * rowspan=2|
 * IT (15%)
 * 129Sb
 * style="text-indent:1em" | 129m2Sb
 * colspan="3" style="text-indent:2em" | 1860.90(10) keV
 * >2 μs
 * (15/2−)
 * style="text-indent:1em" | 129m3Sb
 * colspan="3" style="text-indent:2em" | 2138.9(5) keV
 * 1.1(1) μs
 * (23/2+)
 * 130Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 79
 * 129.911656(18)
 * 39.5(8) min
 * β−
 * 130Te
 * (8−)#
 * style="text-indent:1em" | 130mSb
 * colspan="3" style="text-indent:2em" | 4.80(20) keV
 * 6.3(2) min
 * β−
 * 130Te
 * (4, 5)+
 * 131Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 80
 * 130.911982(22)
 * 23.03(4) min
 * β−
 * 131mTe
 * (7/2+)
 * 132Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 81
 * 131.914467(15)
 * 2.79(5) min
 * β−
 * 132Te
 * (4+)
 * style="text-indent:1em" | 132m1Sb
 * colspan="3" style="text-indent:2em" | 200(30) keV
 * 4.15(5) min
 * β−
 * 132Te
 * (8−)
 * style="text-indent:1em" | 132m2Sb
 * colspan="3" style="text-indent:2em" | 254.5(3) keV
 * 102(4) ns
 * (6−)
 * 133Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 82
 * 132.915252(27)
 * 2.5(1) min
 * β−
 * 133mTe
 * (7/2+)
 * 134Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 83
 * 133.92038(5)
 * 0.78(6) s
 * β−
 * 134Te
 * (0-)
 * rowspan=2 style="text-indent:1em" | 134mSb
 * rowspan=2 colspan="3" style="text-indent:2em" | 80(110) keV
 * rowspan=2|10.07(5) s
 * β− (99.9%)
 * 134Te
 * rowspan=2|(7−)
 * rowspan=2|
 * rowspan=2|
 * β−, n (.091%)
 * 133Te
 * rowspan=2|135Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 84
 * rowspan=2|134.92517(11)
 * rowspan=2|1.68(2) s
 * β− (82.4%)
 * 135Te
 * rowspan=2|(7/2+)
 * rowspan=2|
 * rowspan=2|
 * β−, n (17.6%)
 * 134Te
 * rowspan=2|136Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 85
 * rowspan=2|135.93035(32)#
 * rowspan=2|0.923(14) s
 * β− (83%)
 * 136Te
 * rowspan=2|1−#
 * rowspan=2|
 * rowspan=2|
 * β−, n (17%)
 * 135Te
 * style="text-indent:1em" | 136mSb
 * colspan="3" style="text-indent:2em" | 173(3) keV
 * 570(50) ns
 * 6−#
 * rowspan=2|137Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 86
 * rowspan=2|136.93531(43)#
 * rowspan=2|450(50) ms
 * β−
 * 137Te
 * rowspan=2|7/2+#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 136Te
 * rowspan=2|138Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 87
 * rowspan=2|137.94079(32)#
 * rowspan=2|500# ms [>300 ns]
 * β−
 * 138Te
 * rowspan=2|2−#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 137Te
 * 139Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 88
 * 138.94598(54)#
 * 300# ms [>300 ns]
 * β−
 * 139Te
 * 7/2+#
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 85
 * rowspan=2|135.93035(32)#
 * rowspan=2|0.923(14) s
 * β− (83%)
 * 136Te
 * rowspan=2|1−#
 * rowspan=2|
 * rowspan=2|
 * β−, n (17%)
 * 135Te
 * style="text-indent:1em" | 136mSb
 * colspan="3" style="text-indent:2em" | 173(3) keV
 * 570(50) ns
 * 6−#
 * rowspan=2|137Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 86
 * rowspan=2|136.93531(43)#
 * rowspan=2|450(50) ms
 * β−
 * 137Te
 * rowspan=2|7/2+#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 136Te
 * rowspan=2|138Sb
 * rowspan=2 style="text-align:right" | 51
 * rowspan=2 style="text-align:right" | 87
 * rowspan=2|137.94079(32)#
 * rowspan=2|500# ms [>300 ns]
 * β−
 * 138Te
 * rowspan=2|2−#
 * rowspan=2|
 * rowspan=2|
 * β−, n
 * 137Te
 * 139Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 88
 * 138.94598(54)#
 * 300# ms [>300 ns]
 * β−
 * 139Te
 * 7/2+#
 * β−, n
 * 137Te
 * 139Sb
 * style="text-align:right" | 51
 * style="text-align:right" | 88
 * 138.94598(54)#
 * 300# ms [>300 ns]
 * β−
 * 139Te
 * 7/2+#
 * 7/2+#