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62 promethium ← samarium → europium
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↑
Sm
↓
Pu
General
Name, Symbol, Number samarium, Sm, 62
Chemical series lanthanides
Group, Period, Block n/a, 6, f
Appearance silvery white
Standard atomic weight 150.36(2)  g·mol−1
Electron configuration [Xe] 6s2 4f6
Electrons per shell 2, 8, 18, 24, 8, 2
Physical properties
Phase solid
Density (near r.t.) 7. Promethium (prəˈmiːθiəm/ /proʊˈmiːθiəm is a Chemical element with the symbol Pm and Atomic number 61 Europium (jʊˈroʊpiəm is a Chemical element with the symbol Eu and Atomic number 63 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 52  g·cm−3
Liquid density at m.p. 7. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 16  g·cm−3
Melting point 1345 K
(1072 °C, 1962 °F)
Boiling point 2067 K
(1794 °C, 3261 °F)
Heat of fusion 8. 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 62  kJ·mol−1
Heat of vaporization 165  kJ·mol−1
Specific heat capacity (25 °C) 29. 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 Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 54  J·mol−1·K−1
Vapor pressure
P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 1001 1106 1240 (1421) (1675) (2061)
Atomic properties
Crystal structure rhombohedral
Oxidation states 3
(mildly basic oxide)
Electronegativity 1. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium 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 17 (Pauling scale)
Ionization energies
(more)		 1st:  544. 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 5  kJ·mol−1
2nd:  1070  kJ·mol−1
3rd:  2260  kJ·mol−1
Atomic radius 185  pm
Atomic radius (calc. 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 ) 238  pm
Miscellaneous
Magnetic ordering antiferromagnetic
Electrical resistivity (r.t.) (α, poly) 0. 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 940 µΩ·m
Thermal conductivity (300 K) 13. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 3  W·m−1·K−1
Thermal expansion (r.t.) (α, poly)
12. 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 7 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2130 m/s
Young's modulus (α form) 49. Sound is a vibration that travels through an elastic medium as a Wave. In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material 7  GPa
Shear modulus (α form) 19. In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear 5  GPa
Bulk modulus (α form) 37. 8  GPa
Poisson ratio (α form) 0. Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 274
Vickers hardness 412  MPa
Brinell hardness 441  MPa
CAS registry number 7440-19-9
Selected isotopes
Main article: Isotopes of samarium
iso NA half-life DM DE (MeV) DP
144Sm 3. The Vickers hardness test was developed in 1924 by Smith and Sandland as an alternative method to measure the Hardness of materials The Brinell scale characterizes the indentation Hardness of materials through the scale of penetration of an indenter loaded on a material test-piece CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Naturally occurring Samarium ( Sm) is composed of 4 stable Isotopes 144Sm 150Sm 152Sm and 154Sm and 3 extremely Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide 07% 144Sm is stable with 82 neutrons
146Sm syn 1. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 03×108y α 2. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun 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 529 142Nd
147Sm 14. Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 99% 1. 06×1011y α 2. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun 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 310 143Nd
148Sm 11. Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 24% 7×1015y α 1. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun 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 986 144Nd
149Sm 13. Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 82% >2×1015 y α 1. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun 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 870 145Nd
150Sm 7. Neodymium (ˌniːoʊˈdɪmiəm is a Chemical element with the symbol Nd and Atomic number 60 38% 150Sm is stable with 88 neutrons
152Sm 26. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 75% 152Sm is stable with 90 neutrons
154Sm 22. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 75% 154Sm is stable with 92 neutrons
References

Samarium (pronounced /səˈmɛəriəm/) is a chemical element with the symbol Sm and atomic number 62. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 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

Contents

Notable characteristics

Samarium
Samarium

Samarium is a rare earth metal, with a bright silver luster, that is reasonably stable in air; it ignites in air at 150 °C. The Celsius Temperature scale was previously known as the centigrade scale. Even with long-term storage under mineral oil, samarium is gradually oxidized, with a grayish-yellow powder of the oxide-hydroxide being formed. Three crystal modifications of the metal also exist, with transformations at 734 and 922 °C.

Applications

Uses of Samarium include:

History

Samarium was first discovered spectroscopically in 1853 by Swiss chemist Jean Charles Galissard de Marignac by its sharp absorption lines in didymium, and isolated in Paris in 1879 by French chemist Paul Émile Lecoq de Boisbaudran from the mineral samarskite ((Y,Ce,U,Fe)3(Nb,Ta,Ti)5O16). Year 1853 ( MDCCCLIII) was a Common year starting on Saturday (link will display the full calendar of the Gregorian Calendar (or a Common Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation A chemist is a Scientist trained in the Science of Chemistry. Jean Charles Galissard de Marignac ( April 24, 1817 &ndash April 15, 1894) was a Swiss chemist whose work with A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range compared Didymium (twin element is a mixture of the elements Praseodymium and Neodymium. Paris (ˈpærɨs in English; in French) is the Capital of France and the country's largest city Year 1879 ( MDCCCLXXIX) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common This article is about the country For a topic outline on this subject see List of basic France topics. Paul Émile ( François) Lecoq de Boisbaudran ( April 18, 1838 - May 28, 1912) was a French Chemist born Samarskite or properly samarskite-(Y is a Radioactive Mineral with the Empirical formula: Y 0 Although samarskite was first found in the Urals, by the late 1870s a new deposit had been located in North Carolina, and it was from that source that the samarium-bearing didymium had originated.

The samarskite mineral was named after Vasili Samarsky-Bykhovets, the Chief of Staff (Colonel) of the Russian Corps of Mining Engineers in 1845–1861. Vasili Evgrafovich Samarsky–Bykhovets (Василий Евграфович Самарский–Быховец ( November 7, 1803 &ndash May 31, Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending The name of the element is derived from the name of the mineral, and thus traces back to the name Samarsky-Bykhovets. In this sense samarium was the first chemical element to be named after a living person.

Prior to the advent of ion-exchange separation technology in the 1950s, samarium had no commercial uses in pure form. However, a by-product of the fractional crystallization purification of neodymium was a mixture of samarium and gadolinium that acquired the name of "Lindsay Mix" after the company that made it. This material is thought to have been used for nuclear control rods in some of the early nuclear reactors. Nowadays, a similar commodity product goes under the name of "Samarium-Europium-Gadolinium" concentrate (or SEG concentrate). Europium (jʊˈroʊpiəm is a Chemical element with the symbol Eu and Atomic number 63 Gadolinium (ˌgædəˈlɪniəm is a Chemical element that has the symbol Gd and Atomic number 64 This is prepared by solvent extraction from the mixed lanthanides extracted from bastnäsite (or monazite). Since the heavier lanthanides have the greater affinity for the solvent used, they are easily extracted from the bulk using relatively small proportions of solvent. Not all rare earth producers who process bastnäsite do so on large enough scale to continue onward with the separation of the components of SEG, which typically makes up only one or two percent of the original ore. Such producers will therefore be making SEG with a view to marketing it to the specialized processors. In this manner, the valuable europium content of the ore is rescued for use in phosphor manufacture. Samarium purification follows the removal of the europium. Currently, being in oversupply, samarium oxide is less expensive on a commercial scale than its relative abundance in the ore might suggest.


Occurrence

Samarium is never found free in nature, but, like other rare earth elements, is contained in many minerals, including monazite, bastnasite and samarskite; monazite (in which it occurs up to an extent of 2. In Geology, the Mineral monazite is a reddish-brown Phosphate -containing rare earth metals and an important source of Thorium The mineral bastnäsite is one of a family of three Carbonate - Fluoride minerals Samarskite or properly samarskite-(Y is a Radioactive Mineral with the Empirical formula: Y 0 8%) and bastnäsite are also used as commercial sources. Misch metal containing about 1% of samarium has long been used, but it was not until recent years that relatively pure samarium has been isolated through ion exchange processes, solvent extraction techniques, and electrochemical deposition. Mischmetal (from German: Mischmetall - "mixed metals" is an Alloy of Rare earth elements in various naturally-occurring proportions Ion exchange is an exchange of Ions between two Electrolytes or between an electrolyte Solution and a complex. Liquid-liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two The metal is often prepared by electrolysis of a molten mixture of samarium(III) chloride with sodium chloride or calcium chloride[1]. Overview Samarium(III chloride (SmCl3 also known as samarium trichloride, is a For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Samarium can also be obtained by reducing its oxide with lanthanum. Lanthanum (ˈlænθənəm is a Chemical element with the symbol La and Atomic number 57

Compounds

Compounds of Samarium include:

See also samarium compounds. Fluoride is the reduced form of Fluorine. Both organic and Inorganic compounds containing the element fluorine are considered fluorides Samarium(III fluoride ( Sm[[Fluorine F3]] is a slightly hygroscopic solid Fluoride. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus Samarium(II chloride ( Sm[[Chlorine Cl2]] is a Chemical compound. Overview Samarium(III chloride (SmCl3 also known as samarium trichloride, is a A bromide Ion is a Bromine atom with charge of −1 Compounds with bromine in formal Oxidation state −1 are called bromides An iodide Ion is an iodine atom with a &minus1 charge. Compounds with iodine in formal Oxidation state &minus1 are called iodides Samarium(II iodide (SmI2 is a green solid composed of Samarium and Iodine, with a melting point of 520 °C where the samarium atom has a coordination An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element Samarium(III oxide ( Sm2[[Oxygen O3]] is a Chemical compound. The term sulfide ( sulphide in British English) refers to several types of Chemical compounds containing Sulfur in its lowest Oxidation Samarium(III sulfide ( Sm2[[Sulfur S3]] is a Chemical compound. The selenide Ion is Se2&minus A selenide is a chemical compound in which Selenium serves as an Anion with Oxidation number

Isotopes

Main article: isotopes of samarium

Naturally occurring samarium is composed of 5 stable isotopes, 144Sm, 149Sm, 150Sm, 152Sm and 154Sm, and 2 extremely long-lived radioisotopes, 147Sm (1. Naturally occurring Samarium ( Sm) is composed of 4 stable Isotopes 144Sm 150Sm 152Sm and 154Sm and 3 extremely Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides 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 06×1011y) and 148Sm (7×1015y) and ,with 152Sm being the most abundant (26. 75% natural abundance). In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet

151Sm has a halflife of 90 years, and 145Sm has a halflife of 340 days. is a Radioisotope of Samarium with a Half-life of 90 years undergoing low-energy Beta decay, and has a Fission product yield of Half-Life (computer-game page here It's already listed in the disambiguation page All of the remaining radioisotopes have half-lives that are less than 2 days, and the majority of these have half-lives that are less than 48 seconds. 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 This element also has 5 meta states with the most stable being 141mSm (t½ 22. 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 6 minutes), 143m1Sm (t½ 66 seconds) and 139mSm (t½ 10. 7 seconds).

The primary decay mode before the most abundant stable isotope, 152Sm, 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 152Sm are element Pm (promethium) isotopes, and the primary products after are element Eu (europium) isotopes. In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide Promethium (prəˈmiːθiəm/ /proʊˈmiːθiəm is a Chemical element with the symbol Pm and Atomic number 61 Europium (jʊˈroʊpiəm is a Chemical element with the symbol Eu and Atomic number 63

Natural Samarium has an activity of 128 Bq/g. The becquerel (symbol Bq) is the SI derived unit of radioactivity.

Precautions

As with the other lanthanides, samarium compounds are of low to moderate toxicity, although their toxicity has not been investigated in detail. Toxicity is the degree to which a substance is able to damage an exposed organism

References

  1. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, Oxford, UK, 1984.

External links

Dictionary

samarium

-noun

  1. (chemistry) A metallic chemical element (symbol Sm) with an atomic number of 62.
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