Naturally occurring cadmium (₄₈Cd) 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 Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

. The two natural radioactive isotopes are ¹¹³Cd ( beta decay, half-life is 8.04 × 10¹⁵ years) and ¹¹⁶Cd (two-neutrino double beta decay, half-life is 2.8 × 10¹⁹ years). The other three are ¹⁰⁶Cd, ¹⁰⁸Cd ( double electron capture), and ¹¹⁴Cd (double beta decay); only lower limits on their half-life times have been set. At least three isotopes—¹¹⁰Cd, ¹¹¹Cd, and ¹¹²Cd—are absolutely stable (except, theoretically, to

spontaneous fission Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements. The nuclear binding energy of the elements reaches its maximum at an atomic mass number of about 56 (e.g., iron-56); spontaneous breakdo ...

). Among the isotopes absent in natural cadmium, the most long-lived are ¹⁰⁹Cd with a half-life of 462.6 days, and ¹¹⁵Cd 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 ^113mCd (t_1/2 14.1 years), ^115mCd (t_1/2 44.6 days) and ^117mCd (t_1/2 3.36 hours). The known isotopes of cadmium range in atomic mass from 94.950 u (⁹⁵Cd) to 131.946 u (¹³²Cd). The primary

decay mode Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

before the second most abundant stable isotope, ¹¹²Cd, is electron capture and the primary modes after are beta emission and electron capture. The primary

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps ( ...

before ¹¹²Cd 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

, - , ⁹⁵Cd , style="text-align:right" , 48 , style="text-align:right" , 47 , 94.94987(64)# , 5# ms , , , 9/2+# , , , - , ⁹⁶Cd , style="text-align:right" , 48 , style="text-align:right" , 48 , 95.93977(54)# , 1# s , β⁺ , ⁹⁶Ag , 0+ , , , - , rowspan=2, ⁹⁷Cd , rowspan=2 style="text-align:right" , 48 , rowspan=2 style="text-align:right" , 49 , rowspan=2, 96.93494(43)# , rowspan=2, 2.8(6) s , β⁺ (>99.9%) , ⁹⁷Ag , rowspan=2, 9/2+# , rowspan=2, , rowspan=2, , - , β⁺, p (<.1%) , ⁹⁶Pd , - , rowspan=2, ⁹⁸Cd , rowspan=2 style="text-align:right" , 48 , rowspan=2 style="text-align:right" , 50 , rowspan=2, 97.92740(8) , rowspan=2, 9.2(3) s , β⁺ (99.975%) , ⁹⁸Ag , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺, p (.025%) , ⁹⁷Ag , - , style="text-indent:1em" , ^98mCd , colspan="3" style="text-indent:2em" , 2427.5(6) keV , 190(20) ns , , , 8+# , , , - , rowspan=3, ⁹⁹Cd , rowspan=3 style="text-align:right" , 48 , rowspan=3 style="text-align:right" , 51 , rowspan=3, 98.92501(22)# , rowspan=3, 16(3) s , β⁺ (99.78%) , ⁹⁹Ag , rowspan=3, (5/2+) , rowspan=3, , rowspan=3, , - , β⁺, p (.21%) , ⁹⁸Pd , - , β⁺, α (10⁻⁴%) , ⁹⁵Rh , - , ¹⁰⁰Cd , style="text-align:right" , 48 , style="text-align:right" , 52 , 99.92029(10) , 49.1(5) s , β⁺ , ¹⁰⁰Ag , 0+ , , , - , ¹⁰¹Cd , style="text-align:right" , 48 , style="text-align:right" , 53 , 100.91868(16) , 1.36(5) min , β⁺ , ¹⁰¹Ag , (5/2+) , , , - , ¹⁰²Cd , style="text-align:right" , 48 , style="text-align:right" , 54 , 101.91446(3) , 5.5(5) min , β⁺ , ¹⁰²Ag , 0+ , , , - , ¹⁰³Cd , style="text-align:right" , 48 , style="text-align:right" , 55 , 102.913419(17) , 7.3(1) min , β⁺ , ¹⁰³Ag , 5/2+ , , , - , ¹⁰⁴Cd , style="text-align:right" , 48 , style="text-align:right" , 56 , 103.909849(10) , 57.7(10) min , β⁺ , ¹⁰⁴Ag , 0+ , , , - , ¹⁰⁵Cd , style="text-align:right" , 48 , style="text-align:right" , 57 , 104.909468(12) , 55.5(4) min , β⁺ , ¹⁰⁵Ag , 5/2+ , , , - , ¹⁰⁶Cd , style="text-align:right" , 48 , style="text-align:right" , 58 , 105.906459(6) , colspan=3 align=center, Observationally StableBelieved to decay by β⁺β⁺ to ¹⁰⁶Pd with a half-life over 4.1×10²⁰ years , 0+ , 0.0125(6) , , - , ¹⁰⁷Cd , style="text-align:right" , 48 , style="text-align:right" , 59 , 106.906618(6) , 6.50(2) h , β⁺ , ^107mAg , 5/2+ , , , - , ¹⁰⁸Cd , style="text-align:right" , 48 , style="text-align:right" , 60 , 107.904184(6) , colspan=3 align=center, Observationally StableBelieved to decay by β⁺β⁺ to ¹⁰⁸Pd with a half-life over 4.1×10¹⁷ years , 0+ , 0.0089(3) , , - , ¹⁰⁹Cd , style="text-align:right" , 48 , style="text-align:right" , 61 , 108.904982(4) , 461.4(12) d , EC , ¹⁰⁹Ag , 5/2+ , , , - , style="text-indent:1em" , ^109m1Cd , colspan="3" style="text-indent:2em" , 59.6(4) keV , 12(2) µs , , , 1/2+ , , , - , style="text-indent:1em" , ^109m2Cd , colspan="3" style="text-indent:2em" , 463.0(5) keV , 10.9(5) µs , , , 11/2 , , , - , ¹¹⁰Cd , style="text-align:right" , 48 , style="text-align:right" , 62 , 109.9030021(29) , colspan=3 align=center, StableTheoretically capable of spontaneous fission , 0+ , 0.1249(18) , , - , ¹¹¹Cd

Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release ...

, style="text-align:right" , 48 , style="text-align:right" , 63 , 110.9041781(29) , colspan=3 align=center, Stable , 1/2+ , 0.1280(12) , , - , style="text-indent:1em" , ^111mCd , colspan="3" style="text-indent:2em" , 396.214(21) keV , 48.50(9) min , IT , ¹¹¹Cd , 11/2− , , , - , ¹¹²Cd , style="text-align:right" , 48 , style="text-align:right" , 64 , 111.9027578(29) , colspan=3 align=center, Stable , 0+ , 0.2413(21) , , - , ¹¹³Cd

Primordial Primordial may refer to: * Primordial era, an era after the Big Bang. See Chronology of the universe * Primordial sea (a.k.a. primordial ocean, ooze or soup). See Abiogenesis * Primordial nuclide, nuclides, a few radioactive, that formed before ...

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transfer ...

, style="text-align:right" , 48 , style="text-align:right" , 65 , 112.9044017(29) , 8.04(5)×10¹⁵ y , β⁻ , ¹¹³In , 1/2+ , 0.1222(12) , , - , rowspan=2 style="text-indent:1em" , ^113mCd , rowspan=2 colspan="3" style="text-indent:2em" , 263.54(3) keV , rowspan=2, 14.1(5) y , β⁻ (99.86%) , ¹¹³In , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , IT (.139%) , ''¹¹³Cd'' , - , ¹¹⁴Cd , style="text-align:right" , 48 , style="text-align:right" , 66 , 113.9033585(29) , colspan=3 align=center, Observationally StableBelieved to undergo β⁻β⁻ decay to ¹¹⁴Sn with a half-life over 6.4×10¹⁸ years , 0+ , 0.2873(42) , , - , ¹¹⁵Cd , style="text-align:right" , 48 , style="text-align:right" , 67 , 114.9054310(29) , 53.46(5) h , β⁻ , ^115mIn , 1/2+ , , , - , style="text-indent:1em" , ^115mCd , colspan="3" style="text-indent:2em" , 181.0(5) keV , 44.56(24) d , β⁻ , ^115mIn , (11/2)− , , , - , ¹¹⁶Cd , style="text-align:right" , 48 , style="text-align:right" , 68 , 115.904756(3) , 2.8(2)×10¹⁹ y , β⁻β⁻ , ¹¹⁶Sn , 0+ , 0.0749(18) , , - , ¹¹⁷Cd , style="text-align:right" , 48 , style="text-align:right" , 69 , 116.907219(4) , 2.49(4) h , β⁻ , ^117mIn , 1/2+ , , , - , style="text-indent:1em" , ^117mCd , colspan="3" style="text-indent:2em" , 136.4(2) keV , 3.36(5) h , β⁻ , ^117mIn , (11/2)− , , , - , ¹¹⁸Cd , style="text-align:right" , 48 , style="text-align:right" , 70 , 117.906915(22) , 50.3(2) min , β⁻ , ¹¹⁸In , 0+ , , , - , ¹¹⁹Cd , style="text-align:right" , 48 , style="text-align:right" , 71 , 118.90992(9) , 2.69(2) min , β⁻ , ^119mIn , (3/2+) , , , - , style="text-indent:1em" , ^119mCd , colspan="3" style="text-indent:2em" , 146.54(11) keV , 2.20(2) min , β⁻ , ^119mIn , (11/2−)# , , , - , ¹²⁰Cd , style="text-align:right" , 48 , style="text-align:right" , 72 , 119.90985(2) , 50.80(21) s , β⁻ , ¹²⁰In , 0+ , , , - , ¹²¹Cd , style="text-align:right" , 48 , style="text-align:right" , 73 , 120.91298(9) , 13.5(3) s , β⁻ , ^121mIn , (3/2+) , , , - , style="text-indent:1em" , ^121mCd , colspan="3" style="text-indent:2em" , 214.86(15) keV , 8.3(8) s , β⁻ , ^121mIn , (11/2−) , , , - , ¹²²Cd , style="text-align:right" , 48 , style="text-align:right" , 74 , 121.91333(5) , 5.24(3) s , β⁻ , ¹²²In , 0+ , , , - , ¹²³Cd , style="text-align:right" , 48 , style="text-align:right" , 75 , 122.91700(4) , 2.10(2) s , β⁻ , ^123mIn , (3/2)+ , , , - , rowspan=2 style="text-indent:1em" , ^123mCd , rowspan=2 colspan="3" style="text-indent:2em" , 316.52(23) keV , rowspan=2, 1.82(3) s , β⁻ , ¹²³In , rowspan=2, (11/2−) , rowspan=2, , rowspan=2, , - , IT , ¹²³Cd , - , ¹²⁴Cd , style="text-align:right" , 48 , style="text-align:right" , 76 , 123.91765(7) , 1.25(2) s , β⁻ , ¹²⁴In , 0+ , , , - , ¹²⁵Cd , style="text-align:right" , 48 , style="text-align:right" , 77 , 124.92125(7) , 0.65(2) s , β⁻ , ^125mIn , (3/2+)# , , , - , style="text-indent:1em" , ^125mCd , colspan="3" style="text-indent:2em" , 50(70) keV , 570(90) ms , β⁻ , ¹²⁵In , 11/2−# , , , - , ¹²⁶Cd , style="text-align:right" , 48 , style="text-align:right" , 78 , 125.92235(6) , 0.515(17) s , β⁻ , ¹²⁶In , 0+ , , , - , ¹²⁷Cd , style="text-align:right" , 48 , style="text-align:right" , 79 , 126.92644(8) , 0.37(7) s , β⁻ , ^127mIn , (3/2+) , , , - , ¹²⁸Cd , style="text-align:right" , 48 , style="text-align:right" , 80 , 127.92776(32) , 0.28(4) s , β⁻ , ¹²⁸In , 0+ , , , - , rowspan=2, ¹²⁹Cd , rowspan=2 style="text-align:right" , 48 , rowspan=2 style="text-align:right" , 81 , rowspan=2, 128.93215(32)# , rowspan=2, 242(8) ms , β⁻ (>99.9%) , ¹²⁹In , rowspan=2, 3/2+# , rowspan=2, , rowspan=2, , - , IT (<.1%) , ¹²⁹Cd , - , style="text-indent:1em" , ^129mCd , colspan="3" style="text-indent:2em" , 0(200)# keV , 104(6) ms , , , 11/2−# , , , - , rowspan=2, ¹³⁰Cd , rowspan=2 style="text-align:right" , 48 , rowspan=2 style="text-align:right" , 82 , rowspan=2, 129.9339(3) , rowspan=2, 162(7) ms , β⁻ (96%) , ¹³⁰In , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (4%) , ¹²⁹In , - , ¹³¹Cd , style="text-align:right" , 48 , style="text-align:right" , 83 , 130.94067(32)# , 68(3) ms , , , 7/2−# , , , - , ¹³²Cd , style="text-align:right" , 48 , style="text-align:right" , 84 , 131.94555(54)# , 97(10) ms , , , 0+ , , * Hyperdeformation is predicted to be found in ¹⁰⁷Cd.

Cadmium-113m

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 Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing ...

's burnup; thus, this isotope is not a significant contributor to nuclear waste. Fast fission or fission of some heavier actinides will produce ^113mCd at higher yields.

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Authority control Cadmium Cadmium