Naturally occurring

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

(₅₄Xe) consists of seven

stable A stable is a building in which livestock, especially horses, are kept. It most commonly means a building that is divided into separate stalls for individual animals and livestock. There are many different types of stables in use today; the ...

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass numbers ...

s and two very long-lived isotopes.

Double electron capture Double electron capture is a decay mode of an atomic nucleus. For a nuclide (''A'', ''Z'') with a number of nucleons ''A'' and atomic number ''Z'', double electron capture is only possible if the mass of the nuclide (''A'', ''Z''−2) is lower. I ...

has been observed in ¹²⁴Xe (half-life ) and

double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa, inside an atomic nucleus. As in single beta decay, this process allows the atom to move clos ...

in ¹³⁶Xe (half-life ), which are among the longest measured half-lives of all nuclides. The isotopes ¹²⁶Xe and ¹³⁴Xe are also predicted to undergo double beta decay, but this has never been observed in these isotopes, so they are considered to be stable. Beyond these stable forms, 32 artificial

unstable isotope In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be mar ...

s and various isomers have been studied, the longest-lived of which is ¹²⁷Xe with a

half-life 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 ato ...

of 36.345 days. All other isotopes have half-lives less than 12 days, most less than 20 hours. The shortest-lived isotope, ¹⁰⁸Xe, has a half-life of 58 μs, and is the heaviest known nuclide with equal numbers of protons and neutrons. Of known isomers, the longest-lived is ^131mXe with a half-life of 11.934 days. ¹²⁹Xe is produced by

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For e ...

of ¹²⁹I (

: 16 million years); ^131mXe, ¹³³Xe, ^133mXe, and ¹³⁵Xe are some of the

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 ...

s of both ²³⁵U and ²³⁹Pu, so are used as indicators of

nuclear explosion A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, th ...

s. The artificial isotope ¹³⁵Xe is of considerable significance in the operation of nuclear fission reactors. ¹³⁵Xe has a huge

cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...

for

thermal neutron The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with ...

s, 2.65×10⁶

barns A barn is an agricultural building usually on farms and used for various purposes. In North America, a barn refers to structures that house livestock, including cattle and horses, as well as equipment and fodder, and often grain.Allen G. N ...

, so it acts as a

neutron absorber In applications such as nuclear reactors, a neutron poison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption cross-section. In such applications, absorbing neutrons is normally an undesirable eff ...

or "

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

" that can slow or stop the chain reaction after a period of operation. This was discovered in the earliest nuclear reactors built by the American

Manhattan Project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project ...

for

plutonium Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits ...

production. Because of this effect, designers must make provisions to increase the reactor's reactivity (the number of neutrons per fission that go on to fission other atoms of nuclear fuel) over the initial value needed to start the chain reaction. For the same reason, the fission products produced in a nuclear explosion and a power plant differ significantly as a large share of will absorb neutrons in a steady state reactor, while basically none of the will have had time to decay to Xenon before the explosion of the bomb removes it from the

neutron radiation Neutron radiation is a form of ionizing radiation that presents as free neutrons. Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new isotopes� ...

. Relatively high concentrations of radioactive xenon isotopes are also found emanating from nuclear reactors due to the release of this fission gas from cracked

fuel rod 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 or fissioning of uranium in cooling water. The concentrations of these isotopes are still usually low compared to the naturally occurring radioactive

noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemi ...

²²²Rn. Because xenon is a tracer for two parent isotopes, Xe isotope ratios in

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object en ...

s are a powerful tool for studying the

formation of the solar system The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a ...

. The I-Xe method of

dating Dating is a stage of romantic relationships in which two individuals engage in an activity together, most often with the intention of evaluating each other's suitability as a partner in a future intimate relationship. It falls into the categor ...

gives the time elapsed between

nucleosynthesis Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in ...

and the condensation of a solid object from the

solar nebula The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a ...

(xenon being a gas, only that part of it that formed after condensation will be present inside the object). Xenon isotopes are also a powerful tool for understanding terrestrial differentiation. Excess ¹²⁹Xe found in carbon dioxide well gases from

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

was believed to be from the decay of mantle-derived gases soon after Earth's formation. It has been suggested that the isotopic composition of atmospheric xenon fluctuated prior to the GOE before stabilizing, perhaps as a result of the rise in atmospheric O₂.

List of isotopes

, - , ¹⁰⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 54 , , 58(+106−23) μs , α , ¹⁰⁴Te , 0+ , , , - , ¹⁰⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 55 , , 13(2) ms , α , ¹⁰⁵Te , , , , - , rowspan=2, ¹¹⁰Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 56 , rowspan=2, 109.94428(14) , rowspan=2, 310(190) ms
05(+35−25) ms, β⁺ , ¹¹⁰I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α , ¹⁰⁶Te , - , rowspan=2, ¹¹¹Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 57 , rowspan=2, 110.94160(33)# , rowspan=2, 740(200) ms , β⁺ (90%) , ¹¹¹I , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , α (10%) , ¹⁰⁷Te , - , rowspan=2, ¹¹²Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 58 , rowspan=2, 111.93562(11) , rowspan=2, 2.7(8) s , β⁺ (99.1%) , ¹¹²I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (.9%) , ¹⁰⁸Te , - , rowspan=4, ¹¹³Xe , rowspan=4 style="text-align:right" , 54 , rowspan=4 style="text-align:right" , 59 , rowspan=4, 112.93334(9) , rowspan=4, 2.74(8) s , β⁺ (92.98%) , ¹¹³I , rowspan=4, (5/2+)# , rowspan=4, , rowspan=4, , - , β⁺, p (7%) , ¹¹²Te , - , α (.011%) , ¹⁰⁹Te , - , β⁺, α (.007%) , ¹⁰⁹Sb , - , ¹¹⁴Xe , style="text-align:right" , 54 , style="text-align:right" , 60 , 113.927980(12) , 10.0(4) s , β⁺ , ¹¹⁴I , 0+ , , , - , rowspan=3, ¹¹⁵Xe , rowspan=3 style="text-align:right" , 54 , rowspan=3 style="text-align:right" , 61 , rowspan=3, 114.926294(13) , rowspan=3, 18(4) s , β⁺ (99.65%) , ¹¹⁵I , rowspan=3, (5/2+) , rowspan=3, , rowspan=3, , - , β⁺, p (.34%) , ¹¹⁴Te , - , β⁺, α (3×10⁻⁴%) , ¹¹¹Sb , - , ¹¹⁶Xe , style="text-align:right" , 54 , style="text-align:right" , 62 , 115.921581(14) , 59(2) s , β⁺ , ¹¹⁶I , 0+ , , , - , rowspan=2, ¹¹⁷Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 63 , rowspan=2, 116.920359(11) , rowspan=2, 61(2) s , β⁺ (99.99%) , ¹¹⁷I , rowspan=2, 5/2(+) , rowspan=2, , rowspan=2, , - , β⁺, p (.0029%) , ¹¹⁶Te , - , ¹¹⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 64 , 117.916179(11) , 3.8(9) min , β⁺ , ¹¹⁸I , 0+ , , , - , ¹¹⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 65 , 118.915411(11) , 5.8(3) min , β⁺ , ¹¹⁹I , 5/2(+) , , , - , ¹²⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 66 , 119.911784(13) , 40(1) min , β⁺ , ¹²⁰I , 0+ , , , - , ¹²¹Xe , style="text-align:right" , 54 , style="text-align:right" , 67 , 120.911462(12) , 40.1(20) min , β⁺ , ¹²¹I , (5/2+) , , , - , ¹²²Xe , style="text-align:right" , 54 , style="text-align:right" , 68 , 121.908368(12) , 20.1(1) h , β⁺ , ¹²²I , 0+ , , , - , ¹²³Xe , style="text-align:right" , 54 , style="text-align:right" , 69 , 122.908482(10) , 2.08(2) h , EC , ¹²³I , 1/2+ , , , - , style="text-indent:1em" , ^123mXe , colspan="3" style="text-indent:2em" , 185.18(22) keV , 5.49(26) μs , , , 7/2(−) , , , - , ¹²⁴Xe

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 t ...

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; transferr ...

, style="text-align:right" , 54 , style="text-align:right" , 70 , 123.905893(2) , 1.8(0.5 (stat), 0.1 (sys)) y , Double EC , ¹²⁴Te , 0+ , 9.52(3)×10⁻⁴ , , - , ¹²⁵Xe , style="text-align:right" , 54 , style="text-align:right" , 71 , 124.9063955(20) , 16.9(2) h , β⁺ , ¹²⁵I , 1/2(+) , , , - , style="text-indent:1em" , ^125m1Xe , colspan="3" style="text-indent:2em" , 252.60(14) keV , 56.9(9) s , IT , ¹²⁵Xe , 9/2(−) , , , - , style="text-indent:1em" , ^125m2Xe , colspan="3" style="text-indent:2em" , 295.86(15) keV , 0.14(3) μs , , , 7/2(+) , , , - , ¹²⁶Xe , style="text-align:right" , 54 , style="text-align:right" , 72 , 125.904274(7) , colspan=3 align=center,

Observationally Stable Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes. Th ...

Suspected of undergoing β⁺β⁺ decay to ¹²⁶Te , 0+ , 8.90(2)×10⁻⁴ , , - , ¹²⁷Xe , style="text-align:right" , 54 , style="text-align:right" , 73 , 126.905184(4) , 36.345(3) d , EC , ¹²⁷I , 1/2+ , , , - , style="text-indent:1em" , ^127mXe , colspan="3" style="text-indent:2em" , 297.10(8) keV , 69.2(9) s , IT , ¹²⁷Xe , 9/2− , , , - , ¹²⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 74 , 127.9035313(15) , colspan=3 align=center, StableTheoretically capable of

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 breakdow ...

, 0+ , 0.019102(8) , , - , ¹²⁹XeUsed in a method of

radiodating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...

groundwater and to infer certain events in the Solar System's history , style="text-align:right" , 54 , style="text-align:right" , 75 , 128.9047794(8) , colspan=3 align=center, Stable , 1/2+ , 0.264006(82) , , - , style="text-indent:1em" , ^129mXe , colspan="3" style="text-indent:2em" , 236.14(3) keV , 8.88(2) d , IT , ¹²⁹Xe , 11/2− , , , - , ¹³⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 76 , 129.9035080(8) , colspan=3 align=center, Stable , 0+ , 0.040710(13) , , - , ¹³¹Xe

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" , 54 , style="text-align:right" , 77 , 130.9050824(10) , colspan=3 align=center, Stable , 3/2+ , 0.212324(30) , , - , style="text-indent:1em" , ^131mXe , colspan="3" style="text-indent:2em" , 163.930(8) keV , 11.934(21) d , IT , ¹³¹Xe , 11/2− , , , - , ¹³²Xe , style="text-align:right" , 54 , style="text-align:right" , 78 , 131.9041535(10) , colspan=3 align=center, Stable , 0+ , 0.269086(33) , , - , style="text-indent:1em" , ^132mXe , colspan="3" style="text-indent:2em" , 2752.27(17) keV , 8.39(11) ms , IT , ¹³²Xe , (10+) , , , - , ¹³³XeHas medical uses , style="text-align:right" , 54 , style="text-align:right" , 79 , 132.9059107(26) , 5.2475(5) d , β⁻ , ¹³³Cs , 3/2+ , , , - , style="text-indent:1em" , ^133mXe , colspan="3" style="text-indent:2em" , 233.221(18) keV , 2.19(1) d , IT , ¹³³Xe , 11/2− , , , - , ¹³⁴Xe , style="text-align:right" , 54 , style="text-align:right" , 80 , 133.9053945(9) , colspan=3 align=center, Observationally StableSuspected of undergoing β⁻β⁻ decay to ¹³⁴Ba with a half-life over 11×10¹⁵ years , 0+ , 0.104357(21) , , - , style="text-indent:1em" , ^134m1Xe , colspan="3" style="text-indent:2em" , 1965.5(5) keV , 290(17) ms , IT , ¹³⁴Xe , 7− , , , - , style="text-indent:1em" , ^134m2Xe , colspan="3" style="text-indent:2em" , 3025.2(15) keV , 5(1) μs , , , (10+) , , , - , ¹³⁵XeMost powerful known

, produced in nuclear power plants as a

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 (de ...

of ¹³⁵I, itself a decay product of ¹³⁵Te, a

. Normally absorbs neutrons in the high

neutron flux The neutron flux, φ, is a scalar quantity used in nuclear physics and nuclear reactor physics. It is the total length travelled by all free neutrons per unit time and volume. Equivalently, it can be defined as the number of neutrons travelling ...

environments to become ''¹³⁶Xe''; see

iodine pit The iodine pit, also called the iodine hole or xenon pit, is a temporary disabling of a nuclear reactor due to buildup of short- lived nuclear poisons in the reactor core. The main isotope responsible is 135Xe, mainly produced by natural decay o ...

for more information , style="text-align:right" , 54 , style="text-align:right" , 81 , 134.907227(5) , 9.14(2) h , β⁻ , ¹³⁵Cs , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^135mXe , rowspan=2 colspan="3" style="text-indent:2em" , 526.551(13) keV , rowspan=2, 15.29(5) min , IT (99.99%) , ¹³⁵Xe , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , β⁻ (.004%) , ¹³⁵Cs , - , ¹³⁶Xe

, style="text-align:right" , 54 , style="text-align:right" , 82 , 135.907219(8) , 2.165(0.016 (stat), 0.059 (sys)) y , β⁻β⁻ , ¹³⁶Ba , 0+ , 0.088573(44) , , - , style="text-indent:1em" , ^136mXe , colspan="3" style="text-indent:2em" , 1891.703(14) keV , 2.95(9) μs , , , 6+ , , , - , ¹³⁷Xe , style="text-align:right" , 54 , style="text-align:right" , 83 , 136.911562(8) , 3.818(13) min , β⁻ , ¹³⁷Cs , 7/2− , , , - , ¹³⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 84 , 137.91395(5) , 14.08(8) min , β⁻ , ¹³⁸Cs , 0+ , , , - , ¹³⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 85 , 138.918793(22) , 39.68(14) s , β⁻ , ¹³⁹Cs , 3/2− , , , - , ¹⁴⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 86 , 139.92164(7) , 13.60(10) s , β⁻ , ¹⁴⁰Cs , 0+ , , , - , rowspan=2, ¹⁴¹Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 87 , rowspan=2, 140.92665(10) , rowspan=2, 1.73(1) s , β⁻ (99.45%) , ¹⁴¹Cs , rowspan=2, 5/2(−#) , rowspan=2, , rowspan=2, , - , β⁻, n (.043%) , ¹⁴⁰Cs , - , rowspan=2, ¹⁴²Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 88 , rowspan=2, 141.92971(11) , rowspan=2, 1.22(2) s , β⁻ (99.59%) , ¹⁴²Cs , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (.41%) , ¹⁴¹Cs , - , ¹⁴³Xe , style="text-align:right" , 54 , style="text-align:right" , 89 , 142.93511(21)# , 0.511(6) s , β⁻ , ¹⁴³Cs , 5/2− , , , - , rowspan=2, ¹⁴⁴Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 90 , rowspan=2, 143.93851(32)# , rowspan=2, 0.388(7) s , β⁻ , ¹⁴⁴Cs , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n , ¹⁴³Cs , - , ¹⁴⁵Xe , style="text-align:right" , 54 , style="text-align:right" , 91 , 144.94407(32)# , 188(4) ms , β⁻ , ¹⁴⁵Cs , (3/2−)# , , , - , ¹⁴⁶Xe , style="text-align:right" , 54 , style="text-align:right" , 92 , 145.94775(43)# , 146(6) ms , β⁻ , ¹⁴⁶Cs , 0+ , , , - , rowspan=2, ¹⁴⁷Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 93 , rowspan=2, 146.95356(43)# , rowspan=2, 130(80) ms
.10(+10−5) s, β⁻ , ¹⁴⁷Cs , rowspan=2, 3/2−# , rowspan=2, , rowspan=2, , - , β⁻, n , ¹⁴⁶Cs * The isotopic composition refers to that in air.

Xenon-124

Xenon-124 is an isotope of xenon that undergoes double electron capture to

tellurium Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally fou ...

-124 with a very long half life of years, more than 12 orders of magnitude longer than the age of the universe (). Such decays have been observed in the

XENON1T Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the f ...

detector in 2019, and are the rarest processes ever directly observed. (Even slower decays of other nuclei have been measured, but by detecting decay products that have accumulated over billions of years rather than observing them directly.)

Xenon-133

Xenon-133 (sold as a drug under the brand name ''Xeneisol'',

ATC code The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemical ...

) is an isotope of xenon. It is a

that is

inhaled Inhalation (or Inspiration) happens when air or other gases enter the lungs. Inhalation of air Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. The process is autonomic (though there are exceptions ...

to assess pulmonary function, and to image the

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...

s. It is also used to image blood flow, particularly in the brain. ¹³³Xe is also an important

. It is discharged to the atmosphere in small quantities by some nuclear power plants.

Xenon-135

Xenon-135 is a

radioactive isotope 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; transferr ...

, produced as a

of uranium. It has a

of about 9.2 hours and is the most powerful known

neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behav ...

-absorbing

nuclear poison In applications such as nuclear reactors, a neutron poison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption cross-section. In such applications, absorbing neutrons is normally an undesirable eff ...

(having a neutron absorption cross-section of 2 million

Chart of the Nuclides 13th Edition). The overall yield of xenon-135 from fission is 6.3%, though most of this results from the radioactive decay of fission-produced

tellurium-135 There are 39 known isotopes and 17 nuclear isomers of tellurium (52Te), with atomic masses that range from 104 to 142. These are listed in the table below. Naturally-occurring tellurium on Earth consists of eight isotopes. Two of these have been ...

and

iodine-135 There are 37 known isotopes of iodine (53I) from 108I to 144I; all undergo radioactive decay except 127I, which is stable. Iodine is thus a monoisotopic element. Its longest-lived radioactive isotope, 129I, has a half-life of 15.7 million year ...

. Xe-135 exerts a significant effect on

nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from n ...

operation (

xenon pit The iodine pit, also called the iodine hole or xenon pit, is a temporary disabling of a nuclear reactor due to buildup of short-Half-life, lived nuclear poisons in the reactor core. The main isotope responsible is xenon-135, 135Xe, mainly produced ...

). It is discharged to the atmosphere in small quantities by some nuclear power plants.

Xenon-136

Xenon-136 is an isotope of xenon that undergoes

barium Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The ...

-136 with a very long half life of years, more than 10 orders of magnitude longer than the age of the universe (). It is being used in the

Enriched Xenon Observatory The Enriched Xenon Observatory (EXO) is a particle physics experiment searching for neutrinoless double beta decay of xenon-136 at WIPP near Carlsbad, New Mexico, U.S. Neutrinoless double beta decay (0νββ) detection would prove the Majorana ...

experiment to search for

neutrinoless double beta decay The neutrinoless double beta decay (0νββ) is a commonly proposed and experimentally pursued theoretical radioactive decay process that would prove a Majorana nature of the neutrino particle. To this day, it has not been found. The discovery o ...

References

* Isotope masses fro
Ame2003 Atomic Mass Evaluation
by Georges Audi, Aaldert Hendrik Wapstra, Catherine Thibault, Jean Blachot and Olivier Bersillon in ''Nuclear Physics'' A729 (2003). * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Xenon