# Isotopes of cadmium

Naturally occurring cadmium ($_{48}$Cd) is composed of 8 isotopes. For two of them, natural radioactivity was observed, and three others are predicted to be radioactive but their decays have not been observed, due to extremely long half-lives. The two natural radioactive isotopes are $^{113}$Cd (beta decay, half-life is 8.04 × 10$^{15}$ years) and $^{116}$Cd (two-neutrino double beta decay, half-life is 2.8 × 10$^{19}$ years). The other three are $^{106}$Cd, $^{108}$Cd (double electron capture), and $^{114}$Cd (double beta decay); only lower limits on their half-life times have been set. Three isotopes—$^{110}$Cd, $^{111}$Cd, and $^{112}$Cd—are theoretically stable. Among the isotopes absent in natural cadmium, the most long-lived are $^{109}$Cd with a half-life of 462.6 days, and $^{115}$Cd with a half-life of 53.46 hours. All of the remaining radioactive isotopes have half-lives that are less than 2.5 hours and the majority of these have half-lives that are less than 5 minutes. This element also has 12 known meta states, with the most stable being $^{113m}$Cd (t$_{1/2}$ 14.1 years), $^{115m}$Cd (t$_{1/2}$ 44.6 days) and $^{117m}$Cd (t$_{1/2}$ 3.36 hours).
The known isotopes of cadmium range in atomic mass from 94.950 u ($^{95}$Cd) to 131.946 u ($^{132}$Cd). The primary decay mode before the second most abundant stable isotope, $^{112}$Cd, is electron capture and the primary modes after are beta emission and electron capture. The primary decay product before $^{112}$Cd is element 47 (silver) and the primary product after is element 49 (indium).
A 2021 study has shown at high ionic strengths, Cd isotope fractionation mainly depends on its complexation with carboxylic sites. At low ionic strengths, nonspecific Cd binding induced by electrostatic attractions plays a dominant role and promotes Cd isotope fractionation during complexation.

## List of isotopes

| Nuclide | Z | N | Isotopic mass (Da) | Half-life | Decay mode | Daughter isotope | Spin and parity | Natural abundance (mole fraction) | Natural abundance (mole fraction) |
| Nuclide | Excitation energy | Excitation energy | Excitation energy | Half-life | Decay mode | Daughter isotope | Spin and parity | Normal proportion | Range of variation |
| $^{94}$Cd | 48 | 46 | 93.95659(54)# | 80# ms [>760 ns] | | | 0+ | | |
| $^{95}$Cd | 48 | 47 | 94.94948(61)# | 32(3) ms | β$^+$ (95.4%) | $^{95}$Ag | 9/2+# | | |
| $^{95}$Cd | 48 | 47 | 94.94948(61)# | 32(3) ms | β$^+$, p (4.6%) | $^{94}$Pd | 9/2+# | | |
| $^{96}$Cd | 48 | 48 | 95.94034(44)# | 1.003(47) s | β$^+$ (98.4%) | $^{96}$Ag | 0+ | | |
| $^{96}$Cd | 48 | 48 | 95.94034(44)# | 1.003(47) s | β$^+$, p (1.6%) | $^{95}$Pd | 0+ | | |
| $^{96m1}$Cd | 6000(1400) keV | 6000(1400) keV | 6000(1400) keV | 511(26) ms | β$^+$ (84.6%) | $^{96}$Ag | 16+ | | |
| $^{96m1}$Cd | 6000(1400) keV | 6000(1400) keV | 6000(1400) keV | 511(26) ms | β$^+$, p (15.4%) | $^{95}$Pd | 16+ | | |
| $^{96m2}$Cd | 5605(5) keV | 5605(5) keV | 5605(5) keV | 198(18) ns | IT | $^{96}$Cd | (12−,13−) | | |
| $^{97}$Cd | 48 | 49 | 96.93480(45) | 1.16(5) s | β$^+$ (92.6%) | $^{97}$Ag | (9/2+) | | |
| $^{97}$Cd | 48 | 49 | 96.93480(45) | 1.16(5) s | β$^+$, p (7.4%) | $^{96}$Pd | (9/2+) | | |
| $^{97m1}$Cd | 1245.1(2) keV | 1245.1(2) keV | 1245.1(2) keV | 730(70) μs | IT | $^{97}$Cd | (1/2−) | | |
| $^{97m2}$Cd | 2620(580) keV | 2620(580) keV | 2620(580) keV | 3.86(6) s | β$^+$ (74.9%) | $^{97}$Ag | (25/2+) | | |
| $^{97m2}$Cd | 2620(580) keV | 2620(580) keV | 2620(580) keV | 3.86(6) s | β$^+$, p (25.1%) | $^{96}$Pd | (25/2+) | | |
| $^{98}$Cd | 48 | 50 | 97.927389(56) | 9.29(10) s | β$^+$ (>99.97%) | $^{98}$Ag | 0+ | | |
| $^{98}$Cd | 48 | 50 | 97.927389(56) | 9.29(10) s | β$^+$, p (<0.029%) | $^{97}$Pd | 0+ | | |
| $^{98m1}$Cd | 2428.3(4) keV | 2428.3(4) keV | 2428.3(4) keV | 154(16) ns | IT | $^{98}$Cd | (8+) | | |
| $^{98m2}$Cd | 6635(2) keV | 6635(2) keV | 6635(2) keV | 224(5) ns | IT | $^{98}$Cd | (12+) | | |
| $^{99}$Cd | 48 | 51 | 98.9249258(17) | 17(1) s | β$^+$ (99.79%) | $^{99}$Ag | 5/2+# | | |
| $^{99}$Cd | 48 | 51 | 98.9249258(17) | 17(1) s | β$^+$, p (0.21%) | $^{98}$Pd | 5/2+# | | |
| $^{99}$Cd | 48 | 51 | 98.9249258(17) | 17(1) s | β$^+$, α (<10$^{−4}$%) | $^{95}$Rh | 5/2+# | | |
| $^{100}$Cd | 48 | 52 | 99.9203488(18) | 49.1(5) s | β$^+$ | $^{100}$Ag | 0+ | | |
| $^{101}$Cd | 48 | 53 | 100.9185862(16) | 1.36(5) min | β$^+$ | $^{101}$Ag | 5/2+ | | |
| $^{102}$Cd | 48 | 54 | 101.9144818(18) | 5.5(5) min | β$^+$ | $^{102}$Ag | 0+ | | |
| $^{103}$Cd | 48 | 55 | 102.9134169(19) | 7.3(1) min | β$^+$ | $^{103}$Ag | 5/2+ | | |
| $^{104}$Cd | 48 | 56 | 103.9098562(18) | 57.7(10) min | β$^+$ | $^{104}$Ag | 0+ | | |
| $^{105}$Cd | 48 | 57 | 104.9094639(15) | 55.5(4) min | β$^+$ | $^{105}$Ag | 5/2+ | | |
| $^{105m}$Cd | 2517.6(5) keV | 2517.6(5) keV | 2517.6(5) keV | 4.5(5) μs | IT | $^{105}$Cd | (21/2+) | | |
| $^{106}$Cd | 48 | 58 | 105.9064598(12) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.01245(22) | |
| $^{107}$Cd | 48 | 59 | 106.9066120(18) | 6.50(2) h | β$^+$ | $^{107}$Ag | 5/2+ | | |
| $^{108}$Cd | 48 | 60 | 107.9041836(12) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.00888(11) | |
| $^{109}$Cd | 48 | 61 | 108.9049867(16) | 461.3(5) d | EC | $^{109}$Ag | 5/2+ | | |
| $^{109m1}$Cd | 59.60(7) keV | 59.60(7) keV | 59.60(7) keV | 11.8(16) μs | IT | $^{109}$Cd | 1/2+ | | |
| $^{109m2}$Cd | 463.10(11) keV | 463.10(11) keV | 463.10(11) keV | 10.6(4) μs | IT | $^{109}$Cd | 11/2− | | |
| $^{110}$Cd | 48 | 62 | 109.90300747(41) | Stable | Stable | Stable | 0+ | 0.12470(61) | |
| $^{111}$Cd | 48 | 63 | 110.90418378(38) | Stable | Stable | Stable | 1/2+ | 0.12795(12) | |
| $^{111m}$Cd | 396.214(21) keV | 396.214(21) keV | 396.214(21) keV | 48.50(9) min | IT | $^{111}$Cd | 11/2− | | |
| $^{112}$Cd | 48 | 64 | 111.90276390(27) | Stable | Stable | Stable | 0+ | 0.24109(7) | |
| $^{113}$Cd | 48 | 65 | 112.90440811(26) | 8.04(5)×10$^{15}$ y | β$^−$ | $^{113}$In | 1/2+ | 0.12227(7) | |
| $^{113m}$Cd | 263.54(3) keV | 263.54(3) keV | 263.54(3) keV | 13.89(11) y | β$^−$ (99.90%) | $^{113}$In | 11/2− | | |
| $^{113m}$Cd | 263.54(3) keV | 263.54(3) keV | 263.54(3) keV | 13.89(11) y | IT (0.0964%) | $^{113}$Cd | 11/2− | | |
| $^{114}$Cd | 48 | 66 | 113.90336500(30) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.28754(81) | |
| $^{115}$Cd | 48 | 67 | 114.90543743(70) | 53.46(5) h | β$^−$ | $^{115m}$In | 1/2+ | | |
| $^{115m}$Cd | 181.0(5) keV | 181.0(5) keV | 181.0(5) keV | 44.56(24) d | β$^−$ | $^{115m}$In | 11/2− | | |
| $^{116}$Cd | 48 | 68 | 115.90476323(17) | 2.69(9)×10$^{19}$ y | β$^−$β$^−$ | $^{116}$Sn | 0+ | 0.07512(54) | |
| $^{117}$Cd | 48 | 69 | 116.9072260(11) | 2.503(5) h | β$^−$ | $^{117}$In | 1/2+ | | |
| $^{117m}$Cd | 136.4(2) keV | 136.4(2) keV | 136.4(2) keV | 3.441(9) h | β$^−$ | $^{117}$In | 11/2− | | |
| $^{118}$Cd | 48 | 70 | 117.906922(21) | 50.3(2) min | β$^−$ | $^{118}$In | 0+ | | |
| $^{119}$Cd | 48 | 71 | 118.909847(40) | 2.69(2) min | β$^−$ | $^{119}$In | 1/2+ | | |
| $^{119m}$Cd | 146.54(11) keV | 146.54(11) keV | 146.54(11) keV | 2.20(2) min | β$^−$ | $^{119}$In | 11/2− | | |
| $^{120}$Cd | 48 | 72 | 119.9098681(40) | 50.80(21) s | β$^−$ | $^{120}$In | 0+ | | |
| $^{121}$Cd | 48 | 73 | 120.9129637(21) | 13.5(3) s | β$^−$ | $^{121}$In | 3/2+ | | |
| $^{121m}$Cd | 214.86(15) keV | 214.86(15) keV | 214.86(15) keV | 8.3(8) s | β$^−$ | $^{121}$In | 11/2− | | |
| $^{122}$Cd | 48 | 74 | 121.9134591(25) | 5.98(10) s | β$^−$ | $^{122}$In | 0+ | | |
| $^{123}$Cd | 48 | 75 | 122.9168925(29) | 2.10(2) s | β$^−$ | $^{123}$In | 3/2+ | | |
| $^{123m}$Cd | 143(4) keV | 143(4) keV | 143(4) keV | 1.82(3) s | β$^−$ (?%) | $^{123}$In | 11/2− | | |
| $^{123m}$Cd | 143(4) keV | 143(4) keV | 143(4) keV | 1.82(3) s | IT (?%) | $^{123}$Cd | 11/2− | | |
| $^{124}$Cd | 48 | 76 | 123.9176598(28) | 1.25(2) s | β$^−$ | $^{124}$In | 0+ | | |
| $^{125}$Cd | 48 | 77 | 124.9212576(31) | 680(40) ms | β$^−$ | $^{125}$In | 3/2+ | | |
| $^{125m1}$Cd | 186(4) keV | 186(4) keV | 186(4) keV | 480(30) ms | β$^−$ | $^{125}$In | 11/2− | | |
| $^{125m2}$Cd | 1648(4) keV | 1648(4) keV | 1648(4) keV | 19(3) μs | IT | $^{125}$Cd | (19/2+) | | |
| $^{126}$Cd | 48 | 78 | 125.9224303(25) | 512(5) ms | β$^−$ | $^{126}$In | 0+ | | |
| $^{127}$Cd | 48 | 79 | 126.9262033(67) | 480(100) ms | β$^−$ | $^{127}$In | 3/2+ | | |
| $^{127m1}$Cd | 285(8) keV | 285(8) keV | 285(8) keV | 360(40) ms | β$^−$ | $^{127}$In | 11/2− | | |
| $^{127m2}$Cd | 1845(8) keV | 1845(8) keV | 1845(8) keV | 17.5(3) μs | IT | $^{127}$Cd | (19/2+) | | |
| $^{128}$Cd | 48 | 80 | 127.9278168(69) | 246(2) ms | β$^−$ | $^{128}$In | 0+ | | |
| $^{128m1}$Cd | 1870.5(3) keV | 1870.5(3) keV | 1870.5(3) keV | 270(7) ns | IT | $^{128}$Cd | (5−) | | |
| $^{128m2}$Cd | 2714.6(4) keV | 2714.6(4) keV | 2714.6(4) keV | 3.56(6) μs | IT | $^{128}$Cd | (10+) | | |
| $^{128m2}$Cd | 4286.6(15) keV | 4286.6(15) keV | 4286.6(15) keV | 6.3(8) ms | IT | $^{128}$Cd | (15−) | | |
| $^{129}$Cd | 48 | 81 | 128.9322356(57) | 147(3) ms | β$^−$ (?%) | $^{129}$In | 11/2− | | |
| $^{129}$Cd | 48 | 81 | 128.9322356(57) | 147(3) ms | β$^−$, n (?%) | $^{128}$In | 11/2− | | |
| $^{129m1}$Cd | 343(8) keV | 343(8) keV | 343(8) keV | 157(8) ms | β$^−$ (?%) | $^{129}$In | 3/2+ | | |
| $^{129m1}$Cd | 343(8) keV | 343(8) keV | 343(8) keV | 157(8) ms | β$^−$, n (?%) | $^{128}$In | 3/2+ | | |
| $^{129m2}$Cd | 2283(8) keV | 2283(8) keV | 2283(8) keV | 3.6(2) ms | IT | $^{129}$Cd | (21/2+) | | |
| $^{130}$Cd | 48 | 82 | 129.934388(24) | 126.8(18) ms | β$^−$ (96.5%) | $^{130}$In | 0+ | | |
| $^{130}$Cd | 48 | 82 | 129.934388(24) | 126.8(18) ms | β$^−$, n (3.5%) | $^{129}$In | 0+ | | |
| $^{130m}$Cd | 2129.6(10) keV | 2129.6(10) keV | 2129.6(10) keV | 240(16) ns | IT | $^{130}$Cd | (8+) | | |
| $^{131}$Cd | 48 | 83 | 130.940728(21) | 98(2) ms | β$^−$ (96.5%) | $^{131}$In | 7/2−# | | |
| $^{131}$Cd | 48 | 83 | 130.940728(21) | 98(2) ms | β$^−$, n (3.5%) | $^{130}$In | 7/2−# | | |
| $^{132}$Cd | 48 | 84 | 131.945823(64) | 84(5) ms | β$^−$, n (60%) | $^{131}$In | 0+ | | |
| $^{132}$Cd | 48 | 84 | 131.945823(64) | 84(5) ms | β$^−$ (40%) | $^{132}$In | 0+ | | |
| $^{133}$Cd | 48 | 85 | 132.95261(22)# | 61(6) ms | β$^−$ (?%) | $^{133}$In | 7/2−# | | |
| $^{133}$Cd | 48 | 85 | 132.95261(22)# | 61(6) ms | β$^−$, n (?%) | $^{132}$In | 7/2−# | | |
| $^{134}$Cd | 48 | 86 | 133.95764(32)# | 65(15) ms | β$^−$ | $^{134}$In | 0+ | | |
| This table header & footer: view ||||||||||
* ↑ $^m$Cd – Excited nuclear isomer.
* ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
* ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
* ↑ Bold half-life – nearly stable, half-life longer than age of universe.
* ↑ Modes of decay: EC:Electron capture IT:Isomeric transition n:Neutron emission p:Proton emission
* ↑ Bold italics symbol as daughter – Daughter product is nearly stable.
* ↑ Bold symbol as daughter – Daughter product is stable.
* ↑ ( ) spin value – Indicates spin with weak assignment arguments.
* 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
* ↑ Believed to decay by β$^+$β$^+$ to $^{106}$Pd with a half-life over 1.1×10$^{21}$ years
* ↑ Believed to decay by β$^+$β$^+$ to $^{108}$Pd with a half-life over 4.1×10$^{17}$ years
* 1 2 3 4 5 6 7 Fission product
* 1 2 Primordial radionuclide
* ↑ Believed to undergo β$^−$β$^−$ decay to $^{114}$Sn with a half-life over 9.2×10$^{16}$ years
* Hyperdeformation is predicted to be found in $^{107}$Cd.

## Cadmium-113m

Medium-lived fission productsvte :
| | t$_½$ (year) | Yield (%) | Q (keV) | βγ |
| $^{155}$Eu | 4.76 | 0.0803 | 252 | βγ |
| $^{85}$Kr | 10.76 | 0.2180 | 687 | βγ |
| $^{113m}$Cd | 14.1 | 0.0008 | 316 | β |
| $^{90}$Sr | 28.9 | 4.505 | 2826 | β |
| $^{137}$Cs | 30.23 | 6.337 | 1176 | βγ |
| $^{121m}$Sn | 43.9 | 0.00005 | 390 | βγ |
| $^{151}$Sm | 94.6 | 0.5314 | 77 | β |
Cadmium-113m is a cadmium radioisotope and nuclear isomer with a half-life of 14.1 years. In a normal thermal reactor, it has a very low fission product yield, plus its large neutron capture cross section means that most of even the small amount produced is destroyed in the course of the nuclear fuel's burnup; thus, this isotope is not a significant contributor to nuclear waste.
Fast fission or fission of some heavier actinides will produce $^{113m}$Cd at higher yields.