|
|
| Appearance |
| metallic |
| General properties |
| Name, symbol, number |
promethium, Pm, 61 |
| Pronunciation |
/prɵˈmiːθiəm/ pro-MEE-thee-əm |
| Element category |
lanthanide |
| Group, period, block |
n/a, 6, f |
| Standard atomic weight |
[145] |
| Electron configuration |
[Xe] 4f5 6s2 |
| Electrons per shell |
2, 8, 18, 23, 8, 2 (Image) |
| Physical properties |
| Phase |
solid |
| Density (near r.t.) |
7.26 g·cm−3 |
| Melting point |
1315 K, 1042 °C, 1908 °F |
| Boiling point |
3273 K, 3000 °C, 5432 °F |
| Heat of fusion |
7.13 kJ·mol−1 |
| Heat of vaporization |
289 kJ·mol−1 |
| Atomic properties |
| Oxidation states |
3 (mildly basic oxide) |
| Electronegativity |
? 1.13 (Pauling scale) |
| Ionization energies |
1st: 540 kJ·mol−1 |
| 2nd: 1050 kJ·mol−1 |
| 3rd: 2150 kJ·mol−1 |
| Atomic radius |
183 pm |
| Covalent radius |
199 pm |
| Miscellanea |
| Crystal structure |
hexagonal |
| Magnetic ordering |
paramagnetic[1] |
| Electrical resistivity |
(r.t.) est. 0.75 µΩ·m |
| Thermal conductivity |
17.9 W·m−1·K−1 |
| Thermal expansion |
(r.t.) (α, poly)
est. 11 µm/(m·K) |
| Young's modulus |
(α form) est. 46 GPa |
| Shear modulus |
(α form) est. 18 GPa |
| Bulk modulus |
(α form) est. 33 GPa |
| Poisson ratio |
(α form) est. 0.28 |
| CAS registry number |
7440-12-2 |
| Most stable isotopes |
| Main article: Isotopes of promethium |
|
|
|
· r |
Promethium (
/prɵˈmiːθiəm/ pro-MEE-thee-əm), originally prometheum, is a chemical element with the symbol Pm and atomic number 61. It is notable for being the only element besides technetium all of whose isotopes are radioactive but which is followed in the periodic table by chemical elements with stable isotopes. Chemically, promethium is a lanthanide, which forms salts when combined with other elements; the compounds, however, have not been fully studied. Promethium shows only one stable oxidation state of +3; however, a few +2 compounds may be capable of existence.
In 1902, Bohuslav Brauner suggested there was an element with properties intermediate between those of the known elements neodymium (60) and samarium (62); this was confirmed in 1914 by Henry Moseley who, having measured the atomic numbers of all the elements then known, found there was no element with atomic number 61. In 1926, an Italian and an American group claimed to have isolated a sample of element 61; both "discoveries" were soon proven to be false. In 1938, during a nuclear experiment conducted at Ohio State University, a few radioactive nuclides were produced that certainly were not radioisotopes of neodymium or samarium, but there was a lack of chemical proof that element 61 was produced, and the discovery was not generally recognized. Promethium was first produced and characterized at Oak Ridge National Laboratory in 1945 by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor. The discoverers proposed the name "prometheum" (the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology, who stole fire from Mount Olympus and brought it down to mankind, to symbolize "both the daring and the possible misuse of mankind's intellect." However, a sample of the metal was made only in 1963.
There are three possible sources for promethium: rare decays of natural (primordial) neodymium (producing promethium-150), europium (promethium-147), and uranium (various isotopes). The most stable isotope, promethium-145, has a very low rate of alpha decay, so that the alpha half-life is long enough for the presence of primordial promethium to be theoretically possible; however, this has not been experimentally confirmed. The only isotope used in industry is promethium-147, which is used (as 147Pm2O3) in radioionizators, light producers, and atomic batteries; the last of these are used in guided missiles. Since natural promethium is exceedingly scarce, the element is typically man-made by bombarding uranium-235 (enriched uranium) with thermal neutrons (for promethium-147).
A promethium atom has 61 electrons, arranged in the configuration [Xe]4f56s2.[2] In forming compounds, the atom loses its two outermost electrons and one of the 4f-electrons, which belongs to an open subshell. The element's atomic radius is the third largest among all the lanthanides but is only slightly greater than those of the neighboring elements.[2] It is the only exception to the general trend of the contraction of the atoms with increase of atomic radius (caused by the lanthanide contraction[3]) that is not caused by the filled (or half-filled) 4f-subshell.
Many properties of promethium rely on its position among lanthanides and are intermediate between those of neodymium and samarium. For example, the melting point, the first three ionization energies, and the hydration energy are greater than those of neodymium and lower than those of samarium;[2] similarly, the estimate for the boiling point, ionic (Pm3+) radius, and standard heat of formation of monatomic gas are greater than those of samarium and less those of neodymium.[2]
Promethium belongs to the cerium group of lanthanides and is chemically very similar to the neighboring elements. Because of its instability, chemical studies of promethium are incomplete. Even though a few compounds have been synthesized, they are not fully studied; in general, they tend to be pink or red in color.[5] Treatment of acidic solutions containing Pm3+ ions with ammonia results in a gelatinous light-brown sediment of hydroxide, Pm(OH)3, only 10−29 grams of which dissolve in water.[clarification needed] When dissolved in hydrochloric acid, a water-soluble yellow salt, PmCl3, is produced; similarly, when dissolved in nitric acid, a nitrate results, Pm(NO3)3. The latter is also well-soluble; when dried, it forms pink crystals, similar to Nd(NO3)3. The electron configuration for Pm3+ is [Xe] 4f4, and the colour of the ion is pink. The ground state term symbol is 5I4. Unlike the nitrate, the oxide is similar to the corresponding samarium salt and not the neodymium salt; it is a white powder which changes its structure only at very high temperatures. The sulfate is slightly soluble, like the other cerium group sulfates. Cell parameters have been calculated for its octahydrate; they lead to conclusion that the density of Pm2(SO4)3•8 H2O is 2.86 g•cm−3. The oxalate, Pm2(C2O4)3•10 H2O, has the lowest solubility of all lanthanide oxalates.
Promethium forms only one stable oxidation state, +3, in the form of ions; this is in line with other lanthanides. According to its position in the periodic table, the element cannot be expected to form stable +4 or +2 oxidation states; treating chemical compounds containing Pm3+ ions with strong oxidizing or reducing agents showed that the ion is not easily oxidized or reduced. Calculations show, however, that a few promethium(II) compounds are capable of existence, such as promethium(II) chloride and promethium(II,III) fluoride. Since all cerium group elements (the lighter rare earth elements) form stable diiodides, this may also be true for promethium.
Promethium is the only lanthanide and one of only two elements among the first 82 that has no stable (or even long-lived) isotopes; this is a result of a rarely occurring effect of the liquid drop model and stabilities of neighbor element isotopes; it is also the least stable element of the first 84.[10] The primary decay products are neodymium and samarium isotopes (promethium-146 decays to both, the lighter isotopes generally to neodymium, and the heavier to samarium). Promethium nuclear isomers may decay to other promethium isotopes and one isotope can decay to praseodymium.[10]
The most stable isotope of the element is promethium-145, which has a half-life of 17.7 years via electron capture.[10] Because it has 84 neutrons (two more than 82, which is a magic number which corresponds to a stable neutron configuration), it may emit an alpha particle (which has 2 neutrons) to form praseodymium-141 with 82 neutrons. Thus it is the only promethium isotope with an experimentally observed alpha decay. Its partial half-life for alpha decay is about 6.3×109 years, and the relative probability for a 145Pm nucleus to decay in this way is 2.8×10−7%. Several other Pm isotopes (144Pm, 146Pm, 147Pm etc.) also have a positive energy release for alpha decay; their alpha decays are predicted to occur but have not been observed.
The element also has 18 nuclear isomers, with mass numbers of 133 to 142, 144, 148, 149, 152, and 154 (some mass numbers have more than one isomer). The most stable of them is promethium-148m, with a half-life of 43.1 days; this is longer than the half-lives of the ground states of all promethium isotopes, except only for promethium-143 to 147 (note that promethium-148m has a longer half-life than the ground state, promethium-148).[10]
Pitchblende, a uranium ore and the host for most Earth's promethium
In 1934, Willard Libby found weak beta activity in pure neodymium, which was attributed to a half-life over 1012 years. Almost 20 years later, it was confirmed that the element occurs in natural neodymium in equilibrium in quantities below 10−20 grams of promethium per one gram of neodymium. Earlier failures to find this promethium are probably due to that the time needed for fractional division of rare earth elements is too long and promethium-150 (half-life 2.7 h) completely decays.
Both isotopes of natural europium have larger mass excesses than sums of those of their potential alpha daughters plus that of an alpha particle; therefore, they (stable in practice) may alpha decay.[13] Since the energy of an alpha decay of europium-151 was greater than that of europium-153, it was first studied. Researches at Laboratori Nazionali del Gran Sasso showed that europium-151 experimentally decays to promethium-147 with the half-life of 5×1018 years.[14] It has been shown that europium is "responsible" for about 12 grams of promethium in the Earth's crust.[14] Alpha decays for europium-153 have not been found yet.
Finally, promethium can be formed in nature as a product of spontaneous fission of uranium-238. Only trace amounts can be found in naturally occurring ores: a sample of pitchblende has been found to contain promethium at a concentration of four parts per quintillion (1018) by mass.[15] Uranium is thus "responsible" for 560 g promethium in Earth's crust.[14]
Promethium has also been identified in the spectrum of the star HR 465 in Andromeda; it also has been found in HD 101065 (Przybylski's star) and HD 965.[16]
In 1902, Bohuslav Brauner found out that the difference between neodymium and samarium is the largest of all neighboring lanthanides pairs; as a conclusion, he suggested there was an element with intermediate properties between them.[17] This prediction was supported in 1914 by Henry Moseley who, having discovered that atomic number was an experimentally measurable property of elements, found a few atomic numbers had no element to correspond: the gaps were 43, 61, 72, 75, 85, and 87.[18] With the knowledge of a gap in the periodic table several groups started to search for the predicted element among other rare earths in the natural environment.
The first claim of a discovery was published by Luigi Rolla and Lorenzo Fernandes of Florence, Italy. After separating a mixture of a few rare earth elements nitrate concentrate from the Brazilian mineral monazite by fractionated crystallization, they yielded a solution containing mostly samarium. This solution gave x-ray spectra attributed to samarium and element 61. In honor of their city, they named element 61 "florentium." The results were published in 1926, but the scientists claimed that the experiments were done in 1924.[20][21][22][23][24][25] Also in 1926, a group of scientists from the University of Illinois at Urbana-Champaign, Smith Hopkins and Len Yntema published the discovery of element 61. They named it "illinium," after the university.[26][27][28] Both of these reported discoveries were shown to be erroneous because the spectrum line that "corresponded" to element 61 was identical to that of didymium; the lines thought to belong to element 61 turned out to belong to a few impurities (barium, chromium, and platinum).
In 1934, Josef Mattauch finally formulated the isobar rule. One of the indirect consequences of was this rule was that element 61 was unable to form stable isotopes.[29] In 1938, a nuclear experiment was conducted by H. B. Law et al. at Ohio State University. The nuclides produced certainly were not radioisotopes of neodymium or samarium, and the name "cyclonium" was proposed, but there was a lack of chemical proof that element 61 was produced and the discovery not largely recognized.[5]
Promethium was first produced and characterized at Oak Ridge National Laboratory (Clinton Laboratories at the point) in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell by separation and analysis of the fission products of uranium fuel irradiated in the graphite reactor; however, being too busy with military-related research during World War II, they did not announce their discovery until 1947.[30][31] The original proposed name was "clintonium", after the laboratory where the work was conducted; however, the name "prometheum" was suggested by Grace Mary Coryell, the wife of one of the discoverers.[5] It is derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to mankind[5] and symbolizes "both the daring and the possible misuse of the mankind intellect."[32] The spelling was then changed to "promethium," as this was in closer in accordance with other metals.[5]
In 1963, promethium(III) fluoride was used to make promethium metal. Provisionally purified from impurities of samarium, neodymium, and americium, it was put into a tantalum crucible which was located in another tantalum crucible; the outer one contained lithium metal (10 times excess compared to promethium). After creating a vacuum, the chemicals were mixed to produce promethium metal:
- PmF3 + 3 Li → Pm + 3 LiF
The promethium sample produced was used to measure a few of the metal's properties, such as its melting point.
In 1963, ion-exchange methods were used at ORNL to prepare about ten grams of promethium from nuclear reactor fuel processing wastes.[33][34]
Today, promethium is still recovered from the byproducts of uranium fission; it can also be produced by bombarding 146Nd with neutrons, turning it into 147Nd which decays into 147Pm through beta decay with a half-life of 11 days.[35]
The production methods for different isotopes vary. That for promethium-147 is given as it is the only isotope with industrial applications. Promethium-147 is produced in large quantities (compared to other isotopes) by bombarding uranium-235 with thermal neutrons. The output is relatively high at 2.6%[clarification needed]. Another way to produce promethium-147 is via neodymium-147, which decays to promethium-147 with a short half-life. Neodymium-147 may be obtained either by bombarding enriched neodymium-146 with thermal neutrons[37] or by bombarding a uranium carbide target with energetic protons in a particle accelerator.[38] Another method is to bombard uranium-238 with fast neutrons to cause fast fission, which, among multiple reaction products, creates promethium-147.[39]
As early as the 1960s, Oak Ridge National Laboratory could produce 650 grams of promethium per year. At the time, the United States was the only country to produce it in significant quantities.[41] However large-scale production has now stopped in the U.S., and now the only country that produces promethium-147 on a relatively large scale is Russia.[37] However, as of 2010 the U.S. is planning to build a reactor to resume promethium-147 production, as interest in that nuclide has increased in the 2000s.[37]
File:Pm,61.jpg
Promethium(III) chloride being used as a light source for signals in a heat button
Promethium is most commonly used for research purposes; however, one promethium isotope is used outside laboratories.[5] This is promethium-147, most commonly used as the oxide, obtained in milligram quantities.[5] This isotope does not emit gamma rays, and has a small average run in matter[clarification needed], and a relatively long half-life.
- Radioionizers based on promethium-147 eliminate electrostatic charges by giving off microampere currents.
- As a light source for signals, using phosphor to absorb the beta radiation and produce light. The nuclide does not cause aging of the phosphor, as alpha emitters do. Despite its small size, it provides stability of function for a few years. Originally, radium-226 was used for the purpose, but it was later replaced by promethium-147 and tritium (hydrogen-3).[43] Promethium may be favored to tritium for safety reasons.[44]
- In an atomic battery in which cells capture the emitted beta particles to generate an electric current to be used in guided missiles, watches or radios. They have a useful lifetime of about five years.[5]
- Promethium has possible future uses in portable X-ray sources, and as auxiliary heat or power sources for space probes and satellites[45] (although the alpha emitter plutonium-238 has become standard for most space-exploration related uses[46]).
- Promethium is used to measure the thickness of materials. Detectors can measure the thickness of a piece of metal by measuring the amount of radiation from a promethium sample that passes through the metal. The detectors can automatically halt the production of these metal pieces when too much or too little radiation passes through the metal, indicating that the thickness of the metal is not correct.[47]
The element, like other lanthanides, has no biological role. Promethium-147 can emit X-rays during its beta decay,[48] which are dangerous for all lifeforms. Interactions with tiny quantities of promethium-147 are not hazardous if certain precautions are observed.[49] In general, gloves, footwear covers, safety glasses, and an outer layer or easily removed protective clothing should be used.[50]
It is not known what human organs are affected by interaction with promethium; a possible candidate is the bone tissues.[50] Sealed promethium-147 is not dangerous. However, if the packaging is damaged, then promethium becomes dangerous to the environment and humans. If radioactive contamination is found, the contaminated area should be washed with water and soap, but, even though promethium mainly affects the skin, the skin should not be ripped off. If a promethium leak is found, the area should be identified as hazardous and evacuated, and emergency services must be contacted.[50]
No dangers aside from the radioactivity have been shown.[50]
- ^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
- ^ a b c d Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. p. 1223. ISBN 0080379419.
- ^ Cotton, F. Albert; Wilkinson, Geoffrey (1988), Advanced Inorganic Chemistry (5th ed.), New York: Wiley-Interscience, pp. 776, 955, ISBN 0-471-84997-9
- ^ a b c d e f g h Emsley, John (2001). Nature's building blocks: an A-Z guide to the elements. Oxford University Press. p. 344. ISBN 0-19-850341-5. http://books.google.com/?id=Yhi5X7OwuGkC.
- ^ a b c d G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729: 3–128. Bibcode 2003NuPhA.729....3A. DOI:10.1016/j.nuclphysa.2003.11.001. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- ^ Studenikin, Alexander I. (2009). Particle Physics on the Eve of LHC: Proceedings of the Thirteenth Lomonosov Conference on Elementary Particle Physics. World Scientific. pp. 225–226. ISBN 978-981-283-758-5. http://books.google.ru/books?id=gpCMJ1EyKa8C&pg=PA226&hl=ru&sa=X&ei=ZisLT4GPKISdOufzzdkI&ved=0CDcQ6AEwAA#v=onepage&q&f=false.
- ^ a b c P. Belli, R. Bernabei, F. Cappella, R. Cerulli, C.J. Dai, F.A. Danevich, A. d'Angelo, A. Incicchitti, V.V. Kobychev, S.S. Nagorny, S. Nisi, F. Nozzoli, D. Prosperi, V.I. Tretyak, S.S. Yurchenko (2007). "Search for α decay of natural Europium". Nuclear Physics A 789: 15–29. Bibcode 2007NuPhA.789...15B. DOI:10.1016/j.nuclphysa.2007.03.001.
- ^ Attrep, Moses, Jr.; and P. K. Kuroda (May 1968). "Promethium in pitchblende". Journal of Inorganic and Nuclear Chemistry 30 (3): 699–703. DOI:10.1016/0022-1902(68)80427-0.
- ^ C. R. Cowley, W. P. Bidelman, S. Hubrig, G. Mathys, and D. J. Bord (2004). "On the possible presence of promethium in the spectra of HD 101065 (Przybylski's star) and HD 965". Astronomy & Astrophysics 419 (3): 1087–1093. Bibcode 2004A&A...419.1087C. DOI:10.1051/0004-6361:20035726.
- ^ Laing, Michael (2005). "A Revised Periodic Table: With the Lanthanides Repositioned". Foundations of Chemistry 7 (3): 203–233. DOI:10.1007/s10698-004-5959-9.
- ^ Littlefield, Thomas Albert; Thorley, Norman (1968). Atomic and nuclear physics: an introduction in S.I. units (2nd ed.). Van Nostrand. p. 109.
- ^ (German) Rolla, Luigi; Fernandes, Lorenzo (1926). "Über das Element der Atomnummer 61". Zeitschrift für anorganische und allgemeine Chemie 157: 371. DOI:10.1002/zaac.19261570129.
- ^ Noyes, W. A. (1927). "Florentium or Illinium?". Nature 120 (3009): 14. Bibcode 1927Natur.120...14N. DOI:10.1038/120014c0.
- ^ Rolla, L.; Fernandes, L. (1927). "Florentium or Illinium?". Nature 119 (3000): 637. Bibcode 1927Natur.119..637R. DOI:10.1038/119637a0.
- ^ Rolla, Luigi; Fernandes, Lorenzo (1928). "Florentium. II". Zeitschrift für anorganische und allgemeine Chemie 169: 319. DOI:10.1002/zaac.19281690128.
- ^ Rolla, Luigi; Fernandes, Lorenzo (1927). "Florentium". Zeitschrift für anorganische und allgemeine Chemie 163: 40. DOI:10.1002/zaac.19271630104.
- ^ Rolla, Luigi; Fernandes, Lorenzo (1927). "Über Das Element der Atomnummer 61 (Florentium)". Zeitschrift für anorganische und allgemeine Chemie 160: 190. DOI:10.1002/zaac.19271600119.
- ^ Harris, J. A.; Yntema, L. F.; Hopkins, B. S. (1926). "The Element of Atomic Number 61; Illinium". Nature 117 (2953): 792. Bibcode 1926Natur.117..792H. DOI:10.1038/117792a0.
- ^ Brauner, BOHUSLAV (1926). "The New Element of Atomic Number 61: Illinium". Nature 118 (2959): 84. Bibcode 1926Natur.118...84B. DOI:10.1038/118084b0.
- ^ Meyer, R. J.; Schumacher, G.; Kotowski, A. (1926). "Über das Element 61 (Illinium)". Naturwissenschaften 14 (33): 771. Bibcode 1926NW.....14..771M. DOI:10.1007/BF01490264.
- ^ Thyssen, Pieter; Binnemans, Koen; Shinohara, Hisanori; Saito, Yahachi; Gulay, Lubomir D.; Daszkiewicz, Marek; Yan, Chun-Hua; Yan, Zheng-Guan et al. (2011). Gschneider, Karl A., Jr.; Bünzli, Jean-Claude; Pecharsky, Vitalij K.. eds. Handbook on the Physics and Chemistry of Rare Earths. Amsterdam, The Netherlands: Elsevier. p. 66. ISBN 978-0-444-53590-0. http://books.google.ru/books?id=8SstnPFSzb0C&pg=PA66#v=onepage&q&f=false. Retrieved January 14, 2012.
- ^ Jacob A. Marinsky, Lawrence E. Glendenin, Charles D. Coryell: "The Chemical Identification of Radioisotopes of Neodymium and of Element 61", J. Am. Chem. Soc., 1947, 69 (11), pp. 2781–2785; doi:10.1021/ja01203a059.
- ^ "Discovery of Promethium". ORNL Review 36 (1). 2003. http://www.ornl.gov/info/ornlreview/v36_1_03/article_02.shtml. Retrieved 2006-09-17.
- ^ Wiberg, Egon; Wiberg, Nils; Holleman, Arnold Frederick (2001). Inorganic Chemistry. John Wiley and Sons. p. 1694. ISBN 0-12-352651-5.
- ^ Lee, Chung-Sin; Wang, Yun-Ming; Cheng, Wu-Long; Ting, Gann (1989). "Chemical study on the separation and purification of promethium-147". Journal of Radioanalytical and Nuclear Chemistry Articles 130: 21. DOI:10.1007/BF02037697.
- ^ "ION EXCHANGE PURIFICATION OF PROMETHIUM-147 AND ITS SEPARATION FROM AMERICIUM-241, WITH DIETHYLENETRIAMINEPENTA-ACETIC ACID AS THE ELUANT". http://www.ornl.gov/info/reports/1962/3445605484259.pdf.
- ^ Gagnon, Steve. "The Element Promethium". Jefferson Lab. Science Education. http://education.jlab.org/itselemental/ele061.html. Retrieved 26 February 2012.
- ^ a b c Duggirala, Rajesh; Lal, Amit; Radhakrishnan, Shankar (2010), Radioisotope Thin-Film Powered Microsystems, Springer, p. 12, ISBN 978-1-4419-6762-6
- ^ Hänninen, Pekka; Härmä, Harri (2011), Applications of inorganic mass spectrometry, Springer, p. 144, ISBN 978-3-642-21022-8
- ^ De Laeter, J. R. (2001), Applications of inorganic mass spectrometry, Wiley-IEEE, p. 205
- ^ Gerber, Michele Stenehjem; Findlay, John M. (2007), On the Home Front: The Cold War Legacy of the Hanford Nuclear Site (3rd ed.), University of Nebraska Press, p. 162, ISBN 978-0-8032-5995-9
- ^ Tykva, Richard; Berg, Dieter (2004). Man-made and natural radioactivity in environmental pollution and radiochronology. Springer. p. 78. ISBN 1-4020-1860-6.
- ^ Deeter, David P. (1993), Disease and the Environment, Government Printing Office, pp. 187
- ^ Stwertka, Albert (2002), A guide to the elements, Oxford University Press, p. 154, ISBN 978-0-19-515026-1
- ^ Radioisotope Power Systems Committee, National Research Council U.S. (2009), Radioisotope power systems: an imperative for maintaining U.S. leadership in space exploration, National Academies Press, pp. 8, ISBN 978-0-309-13857-4
- ^ Jones, James William; Haygood, John R. (2011). The Terrorist Effect - Weapons of Mass Disruption: The Danger of Nuclear Terrorism. iUniverse. p. 180. ISBN 978-1-4620-3932-6. http://books.google.ru/books?id=YwE0W6LsxygC&pg=PA180&dq=promethium-147+production+how&hl=ru&sa=X&ei=aKwNT-_hBYeeOo6a3a0H&ved=0CFQQ6AEwBDgK#v=onepage&q=promethium-147%20production%20how&f=false. Retrieved January 13, 2012.
- ^ Simmons, Howard (1964), "Reed Business Information", New Scientist 22 (389): 292
- ^ United States Department of the Army (1987), Operator, organizational, direct support, and general support maintenance manual, pp. a
- ^ a b c d Stuart Hunt & Associates Lt., Radioactive Material Safety Data Sheet
- (Russian) Lavrukhina, A. K.; Pozdnyakov, A. A. (1966). Аналитическая химия технеция, прометия, астатина и франция (Analytical Chemistry of Technetium, Promethium, Astatine, and Francium). Nauka.
vep:Prometii
