Isotopes of palladium
Encyclopedia
Naturally occurring palladium
(Pd) is composed of six stable isotope
s, 102Pd, 104Pd, 105Pd, 106Pd, 108Pd, and 110Pd. The most stable radioisotopes are 107Pd with a half-life
of 6.5 million years, 103Pd with a half-life of 17 days, and 100Pd with a half-life of 3.63 days. Twenty-three other radioisotopes have been characterized with atomic weight
s ranging from 90.949 u
(91Pd) to 123.937 u (124Pd). Most of these have half-lives that are less than a half an hour except 101Pd (half-life: 8.47 hours), 109Pd (half-life: 13.7 hours), and 112Pd (half-life: 21 hours).
The primary decay mode before the most abundant stable isotope, 106Pd, is electron capture
and the primary mode after is beta decay
. The primary decay product
before 106Pd is rhodium
and the primary product after is silver
.
Radiogenic 107Ag is a decay product of 107Pd and was first discovered in the Santa Clara, California
meteorite of 1978. The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. 107Pd versus Ag correlations observed in bodies, which have clearly been melted since accretion of the solar system
, must reflect the presence of short-lived nuclides in the early solar system.
Standard atomic mass: 106.42(1) u
palladium
which has uses in radiation therapy
for prostate cancer
and uveal melanoma
. Palladium-103 may be created from palladium-102. It has a half-life
of 16.99 days and decays by electron capture
to rhodium-103, emitting gamma-rays with 21 keV
of energy
.
-107 is the second longest lived (halflife of 6.5 million years) and least radioactive (decay energy
only 33 KeV
, specific activity
5 Ci/g) of the 7 long-lived fission products. It undergoes pure beta decay
(no gamma radiation) to Ag-107.
Its yield from thermal neutron fission of uranium-235
is 0.1629% per fission, only 1/4 that of iodine-129
, and only 1/40 those of Tc-99, Zr-93, and Cs-135.
Yield from U-233
is slightly lower, but yield from Pu-239 is much higher, 3.3%.
Yields are higher in fast fission
or in fission of heavier nuclei.
According to fission palladium contains the isotopes 104Pd (16.9%),105Pd (29.3%), 106Pd (21.3%), 107Pd (17%), 108Pd (11.7%) and 110Pd (3.8%).
According to another source, the proportion of 107Pd is 9.2% for palladium from thermal neutron fission of U-235
, 11.8% for U-233
, and 20.4% for Pu-239. (and the Pu-239 yield of palladium is about 10 times that of U-235.)
Because of this dilution and because 105Pd has 11 times the neutron absorption cross section
, 107Pd is not amenable to disposal by nuclear transmutation
. However, as a noble metal
, palladium is not as mobile in the environment as iodine or technetium.
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
(Pd) is composed of six stable isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s, 102Pd, 104Pd, 105Pd, 106Pd, 108Pd, and 110Pd. The most stable radioisotopes are 107Pd with 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 6.5 million years, 103Pd with a half-life of 17 days, and 100Pd with a half-life of 3.63 days. Twenty-three other radioisotopes have been characterized with atomic weight
Atomic weight
Atomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element to 1/12 of the mass of an atom of carbon-12...
s ranging from 90.949 u
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
(91Pd) to 123.937 u (124Pd). Most of these have half-lives that are less than a half an hour except 101Pd (half-life: 8.47 hours), 109Pd (half-life: 13.7 hours), and 112Pd (half-life: 21 hours).
The primary decay mode before the most abundant stable isotope, 106Pd, is 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...
and the primary mode after is beta decay
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...
. The primary decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...
before 106Pd is rhodium
Rhodium
Rhodium is a chemical element that is a rare, silvery-white, hard and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope, 103Rh. Naturally occurring rhodium is found as the free metal, alloyed...
and the primary product after is silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
.
Radiogenic 107Ag is a decay product of 107Pd and was first discovered in the Santa Clara, California
Santa Clara, California
Santa Clara , founded in 1777 and incorporated in 1852, is a city in Santa Clara County, in the U.S. state of California. The city is the site of the eighth of 21 California missions, Mission Santa Clara de Asís, and was named after the mission. The Mission and Mission Gardens are located on the...
meteorite of 1978. The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. 107Pd versus Ag correlations observed in bodies, which have clearly been melted since accretion of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
, must reflect the presence of short-lived nuclides in the early solar system.
Standard atomic mass: 106.42(1) u
Palladium-103
Palladium-103 is a radioisotope of the elementChemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
palladium
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
which has uses in radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
for prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
and uveal melanoma
Uveal melanoma
Uveal melanoma is a cancer of the eye involving the iris, ciliary body, or choroid . Tumors arise from the pigment cells that reside within the uvea giving color to the eye...
. Palladium-103 may be created from palladium-102. It 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 16.99 days and decays by 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...
to rhodium-103, emitting gamma-rays with 21 keV
Electronvolt
In physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
of energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
.
Palladium-107
PalladiumPalladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
-107 is the second longest lived (halflife of 6.5 million years) and least radioactive (decay energy
Decay energy
The decay energy is the energy released by a radioactive decay. Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation...
only 33 KeV
Kev
Kev can refer to:*Kev Hawkins, a fictional character.*Kevin, a given name occasionally shortened to "Kev".*Kiloelectronvolt, a unit of energy who symbol is "KeV".* Krefelder Eislauf-VereinKEV can refer to:...
, specific activity
Specific activity
In nuclear sciences and technologies, "activity" is the SI quantity related to the phenomenon of natural and artificial radioactivity. The SI unit of "activity" is becquerel, Bq, while that of "specific activity" is Bq/kg. The old unit of "activity" was curie, Ci, while that of "specific activity"...
5 Ci/g) of the 7 long-lived fission products. It undergoes pure beta decay
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...
(no gamma radiation) to Ag-107.
Its yield from thermal neutron fission of uranium-235
Uranium-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...
is 0.1629% per fission, only 1/4 that of iodine-129
Iodine-129
Iodine-129 is long-lived radioisotope of iodine which occurs naturally, but also is of special interest in the monitoring and effects of man-made nuclear fission decay products, where it serves as both tracer and potential radiological contaminant....
, and only 1/40 those of Tc-99, Zr-93, and Cs-135.
Yield from U-233
Uranium-233
Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....
is slightly lower, but yield from Pu-239 is much higher, 3.3%.
Yields are higher in fast fission
Fast fission
Fast fission is fission that occurs when a heavy atom absorbs a high-energy neutron, called a fast neutron, and splits. Most fissionable materials need thermal neutrons, which move slower.-Fast reactors vs. thermal reactors:...
or in fission of heavier nuclei.
According to fission palladium contains the isotopes 104Pd (16.9%),105Pd (29.3%), 106Pd (21.3%), 107Pd (17%), 108Pd (11.7%) and 110Pd (3.8%).
According to another source, the proportion of 107Pd is 9.2% for palladium from thermal neutron fission of U-235
Uranium-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...
, 11.8% for U-233
Uranium-233
Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....
, and 20.4% for Pu-239. (and the Pu-239 yield of palladium is about 10 times that of U-235.)
Because of this dilution and because 105Pd has 11 times the neutron absorption cross section
Neutron cross-section
In nuclear and particle physics, the concept of a neutron cross section is used to express the likelihood of interaction between an incident neutron and a target nucleus. In conjunction with the neutron flux, it enables the calculation of the reaction rate, for example to derive the thermal power...
, 107Pd is not amenable to disposal by nuclear transmutation
Nuclear transmutation
Nuclear transmutation is the conversion of one chemical element or isotope into another. In other words, atoms of one element can be changed into atoms of other element by 'transmutation'...
. However, as a noble metal
Noble metal
Noble metals are metals that are resistant to corrosion and oxidation in moist air, unlike most base metals. They tend to be precious, often due to their rarity in the Earth's crust...
, palladium is not as mobile in the environment as iodine or technetium.
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-life | 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 | |||||||||
| 91Pd | 46 | 45 | 90.94911(61)# | 10# ms [>1.5 µs] | 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... |
91Rh | 7/2+# | ||
| 92Pd | 46 | 46 | 91.94042(54)# | 1.1(3) s [0.7(+4-2) s] | β+ | 92Rh | 0+ | ||
| 93Pd | 46 | 47 | 92.93591(43)# | 1.07(12) s | β+ | 93Rh | (9/2+) | ||
| 93mPd | 0+X keV | 9.3(+25-17) s | |||||||
| 94Pd | 46 | 48 | 93.92877(43)# | 9.0(5) s | β+ | 94Rh | 0+ | ||
| 94mPd | 4884.4(5) keV | 530(10) ns | (14+) | ||||||
| 95Pd | 46 | 49 | 94.92469(43)# | 10# s | β+ | 95Rh | 9/2+# | ||
| 95mPd | 1860(500)# keV | 13.3(3) s | β+ (94.1%) | 95Rh | (21/2+) | ||||
| 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.... (5%) |
95Pd | ||||||||
| 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... (.9%) |
94Ru | ||||||||
| 96Pd | 46 | 50 | 95.91816(16) | 122(2) s | β+ | 96Rh | 0+ | ||
| 96mPd | 2530.8(1) keV | 1.81(1) µs | 8+ | ||||||
| 97Pd | 46 | 51 | 96.91648(32) | 3.10(9) min | β+ | 97Rh | 5/2+# | ||
| 98Pd | 46 | 52 | 97.912721(23) | 17.7(3) min | β+ | 98Rh | 0+ | ||
| 99Pd | 46 | 53 | 98.911768(16) | 21.4(2) min | β+ | 99Rh | (5/2)+ | ||
| 100Pd | 46 | 54 | 99.908506(12) | 3.63(9) d | EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... |
100Rh | 0+ | ||
| 101Pd | 46 | 55 | 100.908289(19) | 8.47(6) h | β+ | 101Rh | 5/2+ | ||
| 102Pd | 46 | 56 | 101.905609(3) | Observationally StableBelieved to decay by β+β+ to 102Ru | 0+ | 0.0102(1) | |||
| 103PdUsed in medicine | 46 | 57 | 102.906087(3) | 16.991(19) d | EC | 103Rh | 5/2+ | ||
| 103mPd | 784.79(10) keV | 25(2) ns | 11/2- | ||||||
| 104Pd | 46 | 58 | 103.904036(4) | Observationally StableTheoretically 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+ | 0.1114(8) | |||
| 105PdFission 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... |
46 | 59 | 104.905085(4) | Observationally Stable | 5/2+ | 0.2233(8) | |||
| 106Pd | 46 | 60 | 105.903486(4) | Observationally Stable | 0+ | 0.2733(3) | |||
| 107PdLong-lived fission product Long-lived fission product Long-lived fission products are radioactive materials with a long half-life produced by nuclear fission.-Evolution of radioactivity in nuclear waste:... |
46 | 61 | 106.905133(4) | 6.5(3)×106 a | β- | 107Ag | 5/2+ | ||
| 107m1Pd | 115.74(12) keV | 0.85(10) µs | 1/2+ | ||||||
| 107m2Pd | 214.6(3) keV | 21.3(5) s | IT | 107Pd | 11/2- | ||||
| 108Pd | 46 | 62 | 107.903892(4) | Observationally Stable | 0+ | 0.2646(9) | |||
| 109Pd | 46 | 63 | 108.905950(4) | 13.7012(24) h | β- | 109mAg | 5/2+ | ||
| 109m1Pd | 113.400(10) keV | 380(50) ns | 1/2+ | ||||||
| 109m2Pd | 188.990(10) keV | 4.696(3) min | IT | 109Pd | 11/2- | ||||
| 110Pd | 46 | 64 | 109.905153(12) | Observationally StableBelieved to decay by β-β- to 110Cd with 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... over 600×1015 years |
0+ | 0.1172(9) | |||
| 111Pd | 46 | 65 | 110.907671(12) | 23.4(2) min | β- | 111mAg | 5/2+ | ||
| 111mPd | 172.18(8) keV | 5.5(1) h | IT | 111Pd | 11/2- | ||||
| β- | 111mAg | ||||||||
| 112Pd | 46 | 66 | 111.907314(19) | 21.03(5) h | β- | 112Ag | 0+ | ||
| 113Pd | 46 | 67 | 112.91015(4) | 93(5) s | β- | 113mAg | (5/2+) | ||
| 113mPd | 81.1(3) keV | 0.3(1) s | IT | 113Pd | (9/2-) | ||||
| 114Pd | 46 | 68 | 113.910363(25) | 2.42(6) min | β- | 114Ag | 0+ | ||
| 115Pd | 46 | 69 | 114.91368(7) | 25(2) s | β- | 115mAg | (5/2+)# | ||
| 115mPd | 89.18(25) keV | 50(3) s | β- (92%) | 115Ag | (11/2-)# | ||||
| IT (8%) | 115Pd | ||||||||
| 116Pd | 46 | 70 | 115.91416(6) | 11.8(4) s | β- | 116Ag | 0+ | ||
| 117Pd | 46 | 71 | 116.91784(6) | 4.3(3) s | β- | 117mAg | (5/2+) | ||
| 117mPd | 203.2(3) keV | 19.1(7) ms | IT | 117Pd | (11/2-)# | ||||
| 118Pd | 46 | 72 | 117.91898(23) | 1.9(1) s | β- | 118Ag | 0+ | ||
| 119Pd | 46 | 73 | 118.92311(32)# | 0.92(13) s | β- | 119Ag | |||
| 120Pd | 46 | 74 | 119.92469(13) | 0.5(1) s | β- | 120Ag | 0+ | ||
| 121Pd | 46 | 75 | 120.92887(54)# | 400# ms [>300 ns] | β- | 121Ag | |||
| 122Pd | 46 | 76 | 121.93055(43)# | 300# ms [>300 ns] | β- | 122Ag | 0+ | ||
| 123Pd | 46 | 77 | 122.93493(64)# | 200# ms [>300 ns] | β- | 123Ag | |||
| 124Pd | 46 | 78 | 123.93688(54)# | 100# ms [>300 ns] | 0+ | ||||