Naturally occurring

xenon Xenon is a chemical element; it has 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 working animals are kept, especially horses or oxen. The building is usually divided into stalls, and may include storage for equipment and feed. Styles There are many different types of stables in use tod ...

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

s and two very long-lived isotopes. Double electron capture has been observed in ¹²⁴Xe (half-life ) and double beta decay 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 process has never been observed in these isotopes, so they are considered to be stable. Beyond these stable forms, 32 artificial unstable isotopes and various isomers have been studied, the longest-lived of which is ¹²⁷Xe with a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

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 an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...

of ¹²⁹I (

: 16 million years); ^131mXe, ¹³³Xe, ^133mXe, and ¹³⁵Xe are some of the fission products of both ²³⁵U and ²³⁹Pu, so are used as indicators of nuclear explosions. The artificial isotope ¹³⁵Xe is of considerable significance in the operation of nuclear fission reactors. ¹³⁵Xe has a huge cross section for thermal neutrons, 2.65 million barns, so it acts as a neutron absorber or "

poison A poison is any chemical substance that is harmful or lethal to living organisms. 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 figurati ...

" 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 program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...

for

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

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. 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 rods 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 the inert gases, sometimes referred to as aerogens) are the members of Group (periodic table), group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some ...

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

meteorite A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...

s are a powerful tool for studying the formation of the Solar System. The I-Xe method of

dating Dating is a stage of Romance (love), romantic relationships in which individuals engage in activity together, often with the intention of evaluating each other's suitability as a partner in a future intimate relationship. It falls into the cate ...

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 (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 Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

well gases from

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

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

, -id=Xenon-108 , ¹⁰⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 54 , 107.95423(41) , 72(35) μs , α , ¹⁰⁴Te , 0+ , , , -id=Xenon-109 , ¹⁰⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 55 , 108.95043(32) , 13(2) ms , α , ¹⁰⁵Te , (7/2+) , , , -id=Xenon-110 , rowspan=2, ¹¹⁰Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 56 , rowspan=2, 109.94426(11) , rowspan=2, 93(3) ms , α (64%) , ¹⁰⁶Te , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺ (36%) , ¹¹⁰I , -id=Xenon-111 , rowspan=2, ¹¹¹Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 57 , rowspan=2, 110.94147(12)# , rowspan=2, 740(200) ms , β⁺ (89.6%) , ¹¹¹I , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , α (10.4%) , ¹⁰⁷Te , -id=Xenon-112 , rowspan=2, ¹¹²Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 58 , rowspan=2, 111.9355591(89) , rowspan=2, 2.7(8) s , β⁺ (98.8%) , ¹¹²I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (1.2%) , ¹⁰⁸Te , -id=Xenon-113 , rowspan=4, ¹¹³Xe , rowspan=4 style="text-align:right" , 54 , rowspan=4 style="text-align:right" , 59 , rowspan=4, 112.9332217(73) , rowspan=4, 2.74(8) s , β⁺ (92.98%) , ¹¹³I , rowspan=4, 5/2+# , rowspan=4, , rowspan=4, , - , β⁺, p (7%) , ¹¹²Te , - , α (?%) , ¹⁰⁹Te , - , β⁺, α (~0.007%) , ¹⁰⁹Sb , -id=Xenon-113m , style="text-indent:1em" , ^113mXe , colspan="3" style="text-indent:2em" , 403.6(14) keV , 6.9(3) μs , IT , ¹¹³Xe , (11/2−) , , , -id=Xenon-114 , ¹¹⁴Xe , style="text-align:right" , 54 , style="text-align:right" , 60 , 113.927980(12) , 10.0(4) s , β⁺ , ¹¹⁴I , 0+ , , , -id=Xenon-115 , rowspan=2, ¹¹⁵Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 61 , rowspan=2, 114.926294(13) , rowspan=2, 18(3) s , β⁺ (99.66%) , ¹¹⁵I , rowspan=2, (5/2+) , rowspan=2, , rowspan=2, , - , β⁺, p (0.34%) , ¹¹⁴Te , -id=Xenon-116 , ¹¹⁶Xe , style="text-align:right" , 54 , style="text-align:right" , 62 , 115.921581(14) , 59(2) s , β⁺ , ¹¹⁶I , 0+ , , , -id=Xenon-117 , 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⁺ , ¹¹⁷I , rowspan=2, 5/2+ , rowspan=2, , rowspan=2, , - , β⁺, p (0.0029%) , ¹¹⁶Te , -id=Xenon-118 , ¹¹⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 64 , 117.916179(11) , 3.8(9) min , β⁺ , ¹¹⁸I , 0+ , , , -id=Xenon-119 , rowspan=2, ¹¹⁹Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 65 , rowspan=2, 118.915411(11) , rowspan=2, 5.8(3) min , β⁺ (79%) , ¹¹⁹I , rowspan=2, 5/2+ , rowspan=2, , rowspan=2, , - , EC (21%) , ¹¹⁹I , -id=Xenon-120 , ¹²⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 66 , 119.911784(13) , 46.0(6) min , β⁺ , ¹²⁰I , 0+ , , , -id=Xenon-121 , ¹²¹Xe , style="text-align:right" , 54 , style="text-align:right" , 67 , 120.911453(11) , 40.1(20) min , β⁺ , ¹²¹I , 5/2+ , , , -id=Xenon-122 , ¹²²Xe , style="text-align:right" , 54 , style="text-align:right" , 68 , 121.908368(12) , 20.1(1) h , EC , ¹²²I , 0+ , , , -id=Xenon-123 , ¹²³Xe , style="text-align:right" , 54 , style="text-align:right" , 69 , 122.908482(10) , 2.08(2) h , β⁺ , ¹²³I , 1/2+ , , , -id=Xenon-123m , style="text-indent:1em" , ^123mXe , colspan="3" style="text-indent:2em" , 185.18(11) keV , 5.49(26) μs , IT , ¹²³Xe , 7/2− , , , - , ¹²⁴Xe Primordial

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

, style="text-align:right" , 54 , style="text-align:right" , 70 , 123.9058852(15) , 1.8(5 ( stat), 1 ( sys)) y , Double EC , ¹²⁴Te , 0+ , 9.5(5)×10⁻⁴ , , -id=Xenon-125 , ¹²⁵Xe , style="text-align:right" , 54 , style="text-align:right" , 71 , 124.9063876(15) , 16.87(8) h , EC / β⁺ , ¹²⁵I , 1/2+ , , , -id=Xenon-125m1 , style="text-indent:1em" , ^125m1Xe , colspan="3" style="text-indent:2em" , 252.61(14) keV , 56.9(9) s , IT , ¹²⁵Xe , 9/2− , , , -id=Xenon-125m2 , style="text-indent:1em" , ^125m2Xe , colspan="3" style="text-indent:2em" , 295.89(15) keV , 0.14(3) μs , IT , ¹²⁵Xe , 7/2+ , , , -id=Xenon-126 , ¹²⁶Xe , style="text-align:right" , 54 , style="text-align:right" , 72 , 125.904297422(6) , colspan=3 align=center, Observationally StableTheoretically capable of 2EC decay to ¹²⁶Te , 0+ , 8.9(3)×10⁻⁴ , , -id=Xenon-127 , ¹²⁷Xe , style="text-align:right" , 54 , style="text-align:right" , 73 , 126.9051836(44) , 36.342(3) d , EC , ¹²⁷I , 1/2+ , , , -id=Xenon-127m , style="text-indent:1em" , ^127mXe , colspan="3" style="text-indent:2em" , 297.10(8) keV , 69.2(9) s , IT , ¹²⁷Xe , 9/2− , , , -id=Xenon-128 , ¹²⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 74 , 127.9035307534(56) , colspan=3 align=center, Stable , 0+ , 0.01910(13) , , -id=Xenon-128m , style="text-indent:1em" , ^128mXe , colspan="3" style="text-indent:2em" , 2787.2(3) keV , 83(2) ns , IT , ¹²⁸Xe , 8− , , , -id=Xenon-129 , ¹²⁹XeUsed in a method of radiodating groundwater and to infer certain events in the Solar System's history , style="text-align:right" , 54 , style="text-align:right" , 75 , 128.9047808574(54) , colspan=3 align=center, Stable , 1/2+ , 0.26401(138) , , -id=Xenon-129m , style="text-indent:1em" , ^129mXe , colspan="3" style="text-indent:2em" , 236.14(3) keV , 8.88(2) d , IT , ¹²⁹Xe , 11/2− , , , -id=Xenon-130 , ¹³⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 76 , 129.903509346(10) , colspan=3 align=center, Stable , 0+ , 0.04071(22) , -id=Xenon-131 , ¹³¹Xe Fission product , style="text-align:right" , 54 , style="text-align:right" , 77 , 130.9050841281(55) , colspan=3 align=center, Stable , 3/2+ , 0.21232(51) , , -id=Xenon-131m , style="text-indent:1em" , ^131mXe , colspan="3" style="text-indent:2em" , 163.930(8) keV , 11.948(12) d , IT , ¹³¹Xe , 11/2− , , , -id=Xenon-132 , ¹³²Xe , style="text-align:right" , 54 , style="text-align:right" , 78 , 131.9041550835(54) , colspan=3 align=center, Stable , 0+ , 0.26909(55) , , -id=Xenon-132m , style="text-indent:1em" , ^132mXe , colspan="3" style="text-indent:2em" , 2752.21(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) , 5.2474(5) d , β⁻ , ¹³³Cs , 3/2+ , , , -id=Xenon-133m1 , style="text-indent:1em" , ^133m1Xe , colspan="3" style="text-indent:2em" , 233.221(15) keV , 2.198(13) d , IT , ¹³³Xe , 11/2− , , , -id=Xenon-133m2 , style="text-indent:1em" , ^133m2Xe , colspan="3" style="text-indent:2em" , 2147(20)# keV , 8.64(13) ms , IT , ¹³³Xe , (23/2+) , , , -id=Xenon-134 , ¹³⁴Xe , style="text-align:right" , 54 , style="text-align:right" , 80 , 133.905393030(6) , colspan=3 align=center, Observationally Stable , 0+ , 0.10436(35) , , -id=Xenon-134m1 , style="text-indent:1em" , ^134m1Xe , colspan="3" style="text-indent:2em" , 1965.5(5) keV , 290(17) ms , IT , ¹³⁴Xe , 7− , , , -id=Xenon-134m2 , style="text-indent:1em" , ^134m2Xe , colspan="3" style="text-indent:2em" , 3025.2(15) keV , 5(1) μs , IT , ¹³⁴Xe , (10+) , , , - , ¹³⁵XeMost powerful known neutron absorber, 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 ( d ...

of ¹³⁵I, itself a decay product of ¹³⁵Te, a fission product. Normally absorbs neutrons in the high neutron flux environments to become ''¹³⁶Xe''; see iodine pit for more information , style="text-align:right" , 54 , style="text-align:right" , 81 , 134.9072314(39) , 9.14(2) h , β⁻ , ¹³⁵Cs , 3/2+ , , , -id=Xenon-135m , 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 (99.70%) , ¹³⁵Xe , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , β⁻ (0.30%) , ¹³⁵Cs , - , ¹³⁶Xe Primordial

, style="text-align:right" , 54 , style="text-align:right" , 82 , 135.907214474(7) , 2.18(5) y , β⁻β⁻ , ¹³⁶Ba , 0+ , 0.08857(72) , , -id=Xenon-136m , style="text-indent:1em" , ^136mXe , colspan="3" style="text-indent:2em" , 1891.74(7) keV , 2.92(3) μs , IT , ''¹³⁶Xe'' , 6+ , , , -id=Xenon-137 , ¹³⁷Xe , style="text-align:right" , 54 , style="text-align:right" , 83 , 136.91155777(11) , 3.818(13) min , β⁻ , ¹³⁷Cs , 7/2− , , , -id=Xenon-138 , ¹³⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 84 , 137.9141463(30) , 14.14(7) min , β⁻ , ¹³⁸Cs , 0+ , , , -id=Xenon-139 , ¹³⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 85 , 138.9187922(23) , 39.68(14) s , β⁻ , ¹³⁹Cs , 3/2− , , , -id=Xenon-140 , ¹⁴⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 86 , 139.9216458(25) , 13.60(10) s , β⁻ , ¹⁴⁰Cs , 0+ , , , -id=Xenon-141 , rowspan=2, ¹⁴¹Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 87 , rowspan=2, 140.9267872(31) , rowspan=2, 1.73(1) s , β⁻ (99.96%) , ¹⁴¹Cs , rowspan=2, 5/2− , rowspan=2, , rowspan=2, , - , β⁻, n (0.044%) , ¹⁴⁰Cs , -id=Xenon-142 , rowspan=2, ¹⁴²Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 88 , rowspan=2, 141.9299731(29) , rowspan=2, 1.23(2) s , β⁻ (99.63%) , ¹⁴²Cs , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (0.37%) , ¹⁴¹Cs , -id=Xenon-143 , rowspan=2, ¹⁴³Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 89 , rowspan=2, 142.9353696(50) , rowspan=2, 511(6) ms , β⁻ (99.00%) , ¹⁴³Cs , rowspan=2, 5/2− , rowspan=2, , rowspan=2, , - , β⁻, n (1.00%) , ¹⁴²Cs , -id=Xenon-144 , rowspan=2, ¹⁴⁴Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 90 , rowspan=2, 143.9389451(57) , rowspan=2, 0.388(7) s , β⁻ (97.0%) , ¹⁴⁴Cs , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (3.0%) , ¹⁴³Cs , -id=Xenon-145 , rowspan=2, ¹⁴⁵Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 91 , rowspan=2, 144.944720(12) , rowspan=2, 188(4) ms , β⁻ (95.0%) , ¹⁴⁵Cs , rowspan=2, 3/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (5.0%) , ¹⁴⁴Cs , -id=Xenon-146 , rowspan=2, ¹⁴⁶Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 92 , rowspan=2, 145.948518(26) , rowspan=2, 146(6) ms , β⁻ , ¹⁴⁶Cs , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (6.9%) , ¹⁴⁵Cs , -id=Xenon-147 , rowspan=2, ¹⁴⁷Xe , rowspan=2 style="text-align:right" , 54 , rowspan=2 style="text-align:right" , 93 , rowspan=2, 146.95448(22)# , rowspan=2, 88(14) ms , β⁻ (>92%) , ¹⁴⁷Cs , rowspan=2, 3/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<8%) , ¹⁴⁶Cs , -id=Xenon-148 , ¹⁴⁸Xe , style="text-align:right" , 54 , style="text-align:right" , 94 , 147.95851(32)# , 85(15) ms , β⁻ , ¹⁴⁸Cs , 0+ , , , -id=Xenon-149 , ¹⁴⁹Xe , style="text-align:right" , 54 , style="text-align:right" , 95 , 148.96457(32)# , 50# ms
550 ms, , , 3/2−# , , , -id=Xenon-150 , ¹⁵⁰Xe , style="text-align:right" , 54 , style="text-align:right" , 96 , 149.96888(32)# , 40# ms
550 ns , , , 0+ , , * The isotopic composition refers to that in air.

Xenon-124

Xenon-124 is an isotope of xenon that undergoes double electron capture to tellurium-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 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-129

MRI with inhaled Xe-129 shows improved ventilation over time

Xenon-129 is a

that is inhaled to assess pulmonary function, and to image the

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

Xenon-133

Xenon-133 (sold as a drug under the brand name ''Xeneisol'', ATC code ) is an isotope of xenon. It is a

that is inhaled to assess pulmonary function, and to image the

s. It is also used to image blood flow, particularly in the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

. ¹³³Xe is a fission product produced by fission of

uranium-235 Uranium-235 ( or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nat ...

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

Xenon-135

Xenon-135 is a radioactive isotope of

, produced as a fission product 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 , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

-absorbing nuclear poison (having a neutron absorption cross-section of 2 million barnsChart 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 and iodine-135. Xe-135 exerts a significant effect on

nuclear reactor A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...

operation ( xenon pit). 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 double beta decay to barium-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 experiment to search for

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

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

Xenon Xenon is a chemical element; it has 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 ...