Isotopes of molybdenum
Encyclopedia
There are 33 known isotopes of molybdenum (Mo) ranging in atomic mass
from 83 to 115, as well as four metastable nuclear isomer
s. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, six (all but 100Mo) have never been observed to decay, but all are theoretically capable of radioactive decay. All unstable isotopes of molybdenum decay into isotopes of zirconium
, niobium
, technetium
, and ruthenium
.
Molybdenum-100 is the only naturally occurring isotope which is not stable. Molybdenum-100 has a half-life
of approximately 1×1019 y
and undergoes double beta decay
into ruthenium
-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum on Earth. Molybdenum isotopes with mass numbers 111 and up all have half-lives of approximately .15 μs.
Standard atomic mass: 95.96(2) u
target, followed rapidly by extraction. It is used as a parent radioisotope in technetium-99m generator
s to produce the even shorter-lived daughter isotope technetium-99m
, which is used in many medical procedures.
Atomic mass
The atomic mass is the mass of a specific isotope, most often expressed in unified atomic mass units. The atomic mass is the total mass of protons, neutrons and electrons in a single atom....
from 83 to 115, as well as four metastable nuclear isomer
Nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus caused by the excitation of one or more of its nucleons . "Metastable" refers to the fact that these excited states have half-lives more than 100 to 1000 times the half-lives of the other possible excited nuclear states...
s. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, six (all but 100Mo) have never been observed to decay, but all are theoretically capable of radioactive decay. All unstable isotopes of molybdenum decay into isotopes of zirconium
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
, niobium
Niobium
Niobium or columbium , is a chemical element with the symbol Nb and atomic number 41. It's a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite...
, technetium
Technetium
Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature...
, and ruthenium
Ruthenium
Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element...
.
Molybdenum-100 is the only naturally occurring isotope which is not stable. Molybdenum-100 has a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of approximately 1×1019 y
Year
A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....
and undergoes double beta decay
Double beta decay
Double beta decay is a radioactive decay process where a nucleus releases two beta rays as a single process.In double-beta decay, two neutrons in the nucleus are converted to protons, and two electrons and two electron antineutrinos are emitted...
into ruthenium
Ruthenium
Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element...
-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum on Earth. Molybdenum isotopes with mass numbers 111 and up all have half-lives of approximately .15 μs.
Standard atomic mass: 95.96(2) u
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-lifeBold for isotopes with half-lives longer than the age of the universe (nearly stable) | decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 83Mo | 42 | 41 | 82.94874(54)# | 23(19) ms [6(+30-3) ms] |
β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... |
83Nb | 3/2-# | ||
| β+, p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
82Zr | ||||||||
| 84Mo | 42 | 42 | 83.94009(43)# | 3.8(9) ms [3.7(+10-8) s] |
β+ | 84Nb | 0+ | ||
| 85Mo | 42 | 43 | 84.93655(30)# | 3.2(2) s | β+ | 85Nb | (1/2-)# | ||
| 86Mo | 42 | 44 | 85.93070(47) | 19.6(11) s | β+ | 86Nb | 0+ | ||
| 87Mo | 42 | 45 | 86.92733(24) | 14.05(23) s | β+ (85%) | 87Nb | 7/2+# | ||
| β+, p (15%) | 86Zr | ||||||||
| 88Mo | 42 | 46 | 87.921953(22) | 8.0(2) min | β+ | 88Nb | 0+ | ||
| 89Mo | 42 | 47 | 88.919480(17) | 2.11(10) min | β+ | 89Nb | (9/2+) | ||
| 89mMo | 387.5(2) keV | 190(15) ms | IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
89Mo | (1/2-) | ||||
| 90Mo | 42 | 48 | 89.913937(7) | 5.56(9) h | β+ | 90Nb | 0+ | ||
| 90mMo | 2874.73(15) keV | 1.12(5) µs | 8+# | ||||||
| 91Mo | 42 | 49 | 90.911750(12) | 15.49(1) min | β+ | 91Nb | 9/2+ | ||
| 91mMo | 653.01(9) keV | 64.6(6) s | IT (50.1%) | 91Mo | 1/2- | ||||
| β+ (49.9%) | 91Nb | ||||||||
| 92Mo | 42 | 50 | 91.906811(4) | Observationally StableBelieved to decay by β+β+ to 92Zr with a half-life over 190×1018 years | 0+ | 0.1477(31) | |||
| 92mMo | 2760.46(16) keV | 190(3) ns | 8+ | ||||||
| 93Mo | 42 | 51 | 92.906813(4) | 4,000(800) a | EC | 93Nb | 5/2+ | ||
| 93mMo | 2424.89(3) keV | 6.85(7) h | IT (99.88%) | 93Mo | 21/2+ | ||||
| β+ (.12%) | 93Nb | ||||||||
| 94Mo | 42 | 52 | 93.9050883(21) | Observationally StableBelieved to be capable of spontaneous fission Spontaneous fission Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses... |
0+ | 0.0923(10) | |||
| 95MoFission product Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The... |
42 | 53 | 94.9058421(21) | Observationally Stable | 5/2+ | 0.1590(9) | |||
| 96Mo | 42 | 54 | 95.9046795(21) | Observationally Stable | 0+ | 0.1668(1) | |||
| 97Mo | 42 | 55 | 96.9060215(21) | Observationally Stable | 5/2+ | 0.0956(5) | |||
| 98Mo | 42 | 56 | 97.9054082(21) | Observationally StableBelieved to decay by β-β- to 98Ru with a half-life of over 100×1012 years | 0+ | 0.2419(26) | |||
| 99MoUsed to produce Technetium-99m generator A technetium-99m generator, or colloquially a technetium cow or moly cow, is a device used to extract the metastable isotope 99mTc of technetium from a source of decaying molybdenum-99... the medically-useful Nuclear medicine In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs... radioisotope technetium-99m Technetium-99m Technetium-99m is a metastable nuclear isomer of technetium-99, symbolized as 99mTc. The "m" indicates that this is a metastable nuclear isomer, i.e., that its half-life of 6 hours is considerably longer than most nuclear isomers that undergo gamma decay... |
42 | 57 | 98.9077119(21) | 2.7489(6) d | β- | 99mTc | 1/2+ | ||
| 99m1Mo | 97.785(3) keV | 15.5(2) µs | 5/2+ | ||||||
| 99m2Mo | 684.5(4) keV | 0.76(6) µs | 11/2- | ||||||
| 100MoPrimordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma... |
42 | 58 | 99.907477(6) | 8.5(5)×1018 a | β-β- | 100Ru | 0+ | 0.0967(20) | |
| 101Mo | 42 | 59 | 100.910347(6) | 14.61(3) min | β- | 101Tc | 1/2+ | ||
| 102Mo | 42 | 60 | 101.910297(22) | 11.3(2) min | β- | 102Tc | 0+ | ||
| 103Mo | 42 | 61 | 102.91321(7) | 67.5(15) s | β- | 103Tc | (3/2+) | ||
| 104Mo | 42 | 62 | 103.91376(6) | 60(2) s | β- | 104Tc | 0+ | ||
| 105Mo | 42 | 63 | 104.91697(8) | 35.6(16) s | β- | 105Tc | (5/2-) | ||
| 106Mo | 42 | 64 | 105.918137(19) | 8.73(12) s | β- | 106Tc | 0+ | ||
| 107Mo | 42 | 65 | 106.92169(17) | 3.5(5) s | β- | 107Tc | (7/2-) | ||
| 107mMo | 66.3(2) keV | 470(30) ns | (5/2-) | ||||||
| 108Mo | 42 | 66 | 107.92345(21)# | 1.09(2) s | β- | 108Tc | 0+ | ||
| 109Mo | 42 | 67 | 108.92781(32)# | 0.53(6) s | β- | 109Tc | (7/2-)# | ||
| 110Mo | 42 | 68 | 109.92973(43)# | 0.27(1) s | β- (>99.9%) | 110Tc | 0+ | ||
| β-, n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (<.1%) |
109Tc | ||||||||
| 111Mo | 42 | 69 | 110.93441(43)# | 200# ms [>300 ns] |
β- | 111Tc | |||
| 112Mo | 42 | 70 | 111.93684(64)# | 150# ms [>300 ns] |
β- | 112Tc | 0+ | ||
| 113Mo | 42 | 71 | 112.94188(64)# | 100# ms [>300 ns] |
β- | 113Tc | |||
| 114Mo | 42 | 72 | 113.94492(75)# | 80# ms [>300 ns] |
0+ | ||||
| 115Mo | 42 | 73 | 114.95029(86)# | 60# ms [>300 ns] |
|||||
Applications
Molybdenum-99 is produced commercially by intense neutron-bombardment of a highly purified uranium-235Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...
target, followed rapidly by extraction. It is used as a parent radioisotope in technetium-99m generator
Technetium-99m generator
A technetium-99m generator, or colloquially a technetium cow or moly cow, is a device used to extract the metastable isotope 99mTc of technetium from a source of decaying molybdenum-99...
s to produce the even shorter-lived daughter isotope technetium-99m
Technetium-99m
Technetium-99m is a metastable nuclear isomer of technetium-99, symbolized as 99mTc. The "m" indicates that this is a metastable nuclear isomer, i.e., that its half-life of 6 hours is considerably longer than most nuclear isomers that undergo gamma decay...
, which is used in many medical procedures.