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| Name, Symbol, Number | promethium, Pm, 61 | |||||||||||||||||||||||||||
| Chemical series | lanthanides | |||||||||||||||||||||||||||
| Group, Period, Block | n/a, 6, f | |||||||||||||||||||||||||||
| Appearance | metallic | |||||||||||||||||||||||||||
| Standard atomic weight | [145](0) g·mol−1 | |||||||||||||||||||||||||||
| Electron configuration | [Xe] 4f5 6s2 | |||||||||||||||||||||||||||
| Electrons per shell | 2, 8, 18, 23, 8, 2 | |||||||||||||||||||||||||||
| Physical properties | ||||||||||||||||||||||||||||
| Phase | solid | |||||||||||||||||||||||||||
| Density (near r.t.) | 7. Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 Samarium (səˈmɛəriəm is a Chemical element with the symbol Sm and Atomic number 62 Neptunium (nɛpˈtjuːniəm is a Chemical element with the symbol Np and Atomic number 93 This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in Terminology The Trivial name " Rare earths " is sometimes used to describe all the lanthanoids together with Scandium and Yttrium In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Occurrence Scandium yttrium and the Lanthanides (except promethium tend to occur together in the Earth's crust and are relatively abundant compared with most D-block A period 6 element is one of the Chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides The f-block of the Periodic table of the elements consists of those elements (sometimes referred to as the inner transition elements) for which in the The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 26 g·cm−3 | |||||||||||||||||||||||||||
| Melting point | 1315 K (1042 °C, 1908 °F) |
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| Boiling point | 3273 K (3000 °C, 5432 °F) |
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| Heat of fusion | 7. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 13 kJ·mol−1 | |||||||||||||||||||||||||||
| Heat of vaporization | 289 kJ·mol−1 | |||||||||||||||||||||||||||
| Atomic properties | ||||||||||||||||||||||||||||
| Crystal structure | hexagonal | |||||||||||||||||||||||||||
| Oxidation states | 3 (mildly basic oxide) |
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| Electronegativity | ? 1. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 13 (Pauling scale) | |||||||||||||||||||||||||||
| Ionization energies (more) |
1st: 540 kJ·mol−1 | |||||||||||||||||||||||||||
| 2nd: 1050 kJ·mol−1 | ||||||||||||||||||||||||||||
| 3rd: 2150 kJ·mol−1 | ||||||||||||||||||||||||||||
| Atomic radius | 185 pm | |||||||||||||||||||||||||||
| Atomic radius (calc. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth ) | 205 pm | |||||||||||||||||||||||||||
| Miscellaneous | ||||||||||||||||||||||||||||
| Magnetic ordering | no data | |||||||||||||||||||||||||||
| Electrical resistivity | (r.t.) est. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 0. 75 µΩ·m | |||||||||||||||||||||||||||
| Thermal conductivity | (300 K) 17. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 9 W·m−1·K−1 | |||||||||||||||||||||||||||
| Thermal expansion | (r.t.) (α, poly) est. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 11 µm/(m·K) |
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| Young's modulus | (α form) est. In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material 46 GPa | |||||||||||||||||||||||||||
| Shear modulus | (α form) est. In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear 18 GPa | |||||||||||||||||||||||||||
| Bulk modulus | (α form) est. 33 GPa | |||||||||||||||||||||||||||
| Poisson ratio | (α form) est. Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 0. 28 | |||||||||||||||||||||||||||
| CAS registry number | 7440-12-2 | |||||||||||||||||||||||||||
| Selected isotopes | ||||||||||||||||||||||||||||
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Promethium (pronounced /prəˈmiːθiəm/, /proʊˈmiːθiəm/) is a chemical element with the symbol Pm and atomic number 61. Samarium (səˈmɛəriəm is a Chemical element with the symbol Sm and Atomic number 62 Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton It is notable for being the only other radioactive element besides technetium which is followed by chemical elements that have stable isotopes. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides
Contents |
Notable characteristics
Promethium's longest lived isotope 145Pm is a soft beta emitter with a half-life of 17. Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 7 years. It does not emit gamma rays, but beta particles impinging on elements of high atomic numbers can generate X-rays, and a sample of 145Pm does produce some such soft X-ray radiation in addition to beta particles. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions X-radiation (composed of X-rays) is a form of Electromagnetic radiation.
Pure promethium exists in two allotropic forms, and its chemistry is similar to other lanthanides. Allotropy (Gr allos, other and tropos, manner is a behavior exhibited by certain Chemical elements these elements can exist in two or more different Terminology The Trivial name " Rare earths " is sometimes used to describe all the lanthanoids together with Scandium and Yttrium Promethium salts luminesce in the dark with a pale blue or greenish glow, due to their high radioactivity. Promethium can be found in traces in some uranium ores, as a fission product. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Newly made promethium is also seen in the spectra of some stars.
Applications
Uses for promethium include:
- As a beta radiation source for thickness gauges.
- As a light source for signals that require reliable, independent operation (using phosphor to absorb the beta radiation and produce light). A phosphor is a substance that exhibits the phenomenon of Phosphorescence (sustained glowing after exposure to energized particles such as Electrons
- In a nuclear battery in which photocells convert the light into electric current, yielding a useful life of about five years, using Pm-147. The terms atomic battery, nuclear battery, tritium battery and radioisotope battery are used to describe a device which uses the emissions from a Radioactive
- Promethium(III) chloride (PmCl3) mixed with zinc sulfide (ZnS) was used for time as a major luminous paint for watches after radium was discontinued. Zinc sulfide (or zinc sulphide is a Chemical compound with the formula Zn[[Sulfur S]] Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 This mixture is still occasionally used for some luminous paint applications (though most such uses with radioactive materials have switched to tritium for safety reasons). Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen.
- Promethium has a possible future uses in portable X-ray sources, and as auxiliary heat or power sources for space probes and satellites (although the alpha emitter plutonium-238 has become standard for most space-exploration related uses – see Radioisotope thermoelectric generators). Plutonium 238, is a Radioactive isotope of Plutonium with a half-life of 87 A radioisotope thermoelectric generator ( RTG, RITEG) is an Electrical generator which obtains its power from Radioactive decay.
History
The existence of promethium was first predicted by Bohuslav Brauner in 1902; this prediction was supported by Henry Moseley in 1914, who found a gap for a missing element which would have atomic number 61, but was unknown (however, Moseley of course had no sample of the element to verify this). Year 1902 ( MCMII) was a Common year starting on Wednesday (link will display calendar of the Gregorian calendar (or a Common year starting Henry Gwyn Jeffreys Moseley ( November 23, 1887 – August 10, 1915) was an English physicist. Year 1914 ( MCMXIV) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Common year Several groups claimed to have produced the element, but they could not confirm their discoveries because of the difficulty of separating promethium from other elements. Promethium was first produced and proved to exist at Oak Ridge National Laboratory (ORNL) in 1945 by Jacob A. Marinsky, Lawrence E. Oak Ridge National Laboratory ( ORNL) is a multiprogram science and technology National laboratory managed for the United States Department of Energy by Year 1945 ( MCMXLV) was a Common year starting on Monday (link will display the full calendar Jacob A Marinsky (1918 &ndash September 1, 2005) was a Chemist and Writer who was the co-discoverer of the element Promethium in 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 defense-related research during World War II, they did not announce their discovery until 1947. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the There are several types of graphite moderated Nuclear reactors that have been used in commercial Electricity generation: Gas-cooled World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar. [1] The name promethium is derived from Prometheus, the Titan, in Greek mythology, who stole the fire from Mount Olympus and brought it down to mankind. In Greek mythology, Prometheus (Προμηθεύς "forethought" is a Titan known for his wily intelligence who stole Fire from Zeus Greek mythology is the body of stories belonging to the ancient Greeks concerning their gods and Heroes the nature of the world and the origins and significance The name was suggested by Grace Mary Coryell, Charles Coryell's wife, who felt that they were stealing fire from the gods.
In 1963, ion-exchange methods were used at ORNL to prepare about 10 grams of promethium from nuclear reactor fuel processing wastes. Year 1963 ( MCMLXIII) was a Common year starting on Tuesday (link will display full calendar of the Gregorian calendar.
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. This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron.
Occurrence
Promethium can be formed in nature as a product of spontaneous fission of uranium-238 and alpha decay of europium-151. Spontaneous fission (SF is a form of Radioactive decay characteristic of very heavy Isotopes and is theoretically possible for any atomic nucleus whose mass is greater Uranium-238 (U-238 is the most common isotope of Uranium found in nature Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle Europium (jʊˈroʊpiəm is a Chemical element with the symbol Eu and Atomic number 63 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. [2] It was calculated that the equilibrium mass of promethium in the earth crust is about 560 g due to uranium fission and about 12 g due to the recently observed alpha decay of europium-151 [3]
Promethium has also been identified in the spectrum of the star HR 465 in Andromeda, and possibly HD 101065 (Przybylski's star) and HD 965. In Geology, a crust is the outermost solid shell of a planet or moon HR 465 ( GY Andromedae or GY And) is an Alpha2 Canum Venaticorum type Variable star in the Constellation Andromeda. Andromeda ( is a Constellation named for the princess Andromeda ( Greek Ανδρομέδη = guardian of the men) a character in Przybylski's Star (or HD 101065) is a peculiar star that is located about 410 Light years from the Sun in the Constellation Centaurus [4]
Compounds
Promethium compounds include:
- Chlorides
- PmCl3
- Bromides
- PmBr3
- Oxides
Isotopes
Thirty-six radioisotopes of promethium have been characterized, with the most stable being 145Pm with a half-life of 17. Promethium(III oxide is a Promethium Compound with the formula Pm2O3 36 Radioisotopes of Promethium ( Pm) have been characterized with the most stable being 145Pm with a Half-life of 17 A radionuclide is an Atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created Half-Life (computer-game page here It's already listed in the disambiguation page 7 years, 146Pm with a half-life of 5. 53 years, and 147Pm with a half-life of 2. 6234 years. All of the remaining radioactive isotopes have half-lives that are less than 364 days, and the majority of these have half lives that are less than 27 seconds. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. This element also has 11 meta states with the most stable being 148Pmm (T½ 41. A nuclear isomer is a Metastable state of an Atomic nucleus caused by the excitation of one or more of its Nucleons A nuclear isomer occupies 29 days), 152Pmm2 (T½ 13. 8 minutes) and 152Pmm (T½ 7. 52 minutes).
The isotopes of promethium range in atomic weight from 127. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass 9482600 u (128Pm) to 162. The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express 9535200 u (163Pm). The primary decay mode before the longest-lived isotope, 145Pm, is electron capture, and the primary mode after is beta minus decay. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted The primary decay products before 145Pm are neodymium (Nd) isotopes and the primary products after are samarium (Sm) isotopes. In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 Samarium (səˈmɛəriəm is a Chemical element with the symbol Sm and Atomic number 62
Stability of promethium isotopes
Besides technetium, promethium is one of the two elements with atomic number less than 83 that have only unstable isotopes, which is a rarely occurring effect of the liquid drop model and stabilities of neighbor element isotopes. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. In Nuclear physics, the semi-empirical mass formula ( SEMF) sometimes also called Weizsäcker's formula is a formula used to approximate the Mass
Precautions
Promethium must be handled with great care because of its high radioactivity. In particular, promethium can emit X-rays during its beta decay. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted Its half-life is less than that of plutonium-239 by a factor of about 1350, and its biological toxicity is correspondingly higher. Promethium has no biological role.
References
- ^ "Discovery of Promethium" (2003). ORNL Review 36 (1). Oak Ridge National Laboratory ( ORNL) is a multiprogram science and technology National laboratory managed for the United States Department of Energy by
- ^ Attrep, Moses, Jr. ; and P. K. Kuroda (May 1968). "Promethium in pitchblende". Journal of Inorganic and Nuclear Chemistry 30 (3): 699–703. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ 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. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ 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: 1087–1093. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
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