Lanthanum

Last updated
Lanthanum, 57La
Lanthanum-2.jpg
Lanthanum
Pronunciation /ˈlænθənəm/ (LAN-thə-nəm)
Appearancesilvery white
Standard atomic weight Ar°(La)
Lanthanum in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


La

Ac
bariumlanthanumcerium
Atomic number (Z)57
Group f-block groups (no number)
Period period 6
Block   f-block
Electron configuration [ Xe ] 5d1 6s2
Electrons per shell2, 8, 18, 18, 9, 2
Physical properties
Phase at  STP solid
Melting point 1193  K (920 °C,1688 °F)
Boiling point 3737 K(3464 °C,6267 °F)
Density (near r.t.)6.162 g/cm3
when liquid (at m.p.)5.94 g/cm3
Heat of fusion 6.20  kJ/mol
Heat of vaporization 400 kJ/mol
Molar heat capacity 27.11 J/(mol·K)
Vapor pressure (extrapolated)
P (Pa)1101001 k10 k100 k
at T (K)200522082458277231783726
Atomic properties
Oxidation states 0, [3] +1, [4] +2, +3 (a strongly basic oxide)
Electronegativity Pauling scale: 1.10
Ionization energies
  • 1st: 538.1 kJ/mol
  • 2nd: 1067 kJ/mol
  • 3rd: 1850.3 kJ/mol
Atomic radius empirical:187  pm
Covalent radius 207±8 pm
Lanthanum spectrum visible.png
Spectral lines of lanthanum
Other properties
Natural occurrence primordial
Crystal structure double hexagonal close-packed (dhcp)
Hexagonal.svg
Speed of sound thin rod2475 m/s(at 20 °C)
Thermal expansion α, poly: 12.1 µm/(m⋅K)(at r.t.)
Thermal conductivity 13.4 W/(m⋅K)
Electrical resistivity α, poly: 615 nΩ⋅m(at r.t.)
Magnetic ordering paramagnetic [5]
Molar magnetic susceptibility +118.0×10−6 cm3/mol(298 K) [6]
Young's modulus α form: 36.6 GPa
Shear modulus α form: 14.3 GPa
Bulk modulus α form: 27.9 GPa
Poisson ratio α form: 0.280
Mohs hardness 2.5
Vickers hardness 360–1750 MPa
Brinell hardness 350–400 MPa
CAS Number 7439-91-0
History
Discovery Carl Gustaf Mosander (1838)
Isotopes of lanthanum
Main isotopes [7] Decay
abun­dance half-life (t1/2) mode pro­duct
137La synth 6×104 y ε 137Ba
138La0.089%1.05×1011 yε 138Ba
β 138Ce
139La99.911% stable
Symbol category class.svg  Category: Lanthanum
| references

Lanthanum is a chemical element; it has symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which lanthanum is the first and the prototype. Lanthanum is traditionally counted among the rare earth elements. Like most other rare earth elements, the usual oxidation state is +3, although some compounds are known with oxidation state +2. Lanthanum has no biological role in humans but is essential to some bacteria. It is not particularly toxic to humans but does show some antimicrobial activity.

Contents

Lanthanum usually occurs together with cerium and the other rare earth elements. Lanthanum was first found by the Swedish chemist Carl Gustaf Mosander in 1839 as an impurity in cerium nitrate – hence the name lanthanum, from the Ancient Greek λανθάνειν (lanthanein), meaning 'to lie hidden'. Although it is classified as a rare earth element, lanthanum is the 28th most abundant element in the Earth's crust, almost three times as abundant as lead. In minerals such as monazite and bastnäsite, lanthanum composes about a quarter of the lanthanide content. [8] It is extracted from those minerals by a process of such complexity that pure lanthanum metal was not isolated until 1923.

Lanthanum compounds have numerous applications as catalysts, additives in glass, carbon arc lamps for studio lights and projectors, ignition elements in lighters and torches, electron cathodes, scintillators, gas tungsten arc welding electrodes, and other things. Lanthanum carbonate is used as a phosphate binder in cases of high levels of phosphate in the blood seen with kidney failure.

Characteristics

Physical

Lanthanum is the first element and prototype of the lanthanide series. In the periodic table, it appears to the right of the alkaline earth metal barium and to the left of the lanthanide cerium. Lanthanum is generally considered the first of the f-block elements by authors writing on the subject. [9] [10] [11] [12] [13] The 57 electrons of a lanthanum atom are arranged in the configuration [Xe]5d16s2, with three valence electrons outside the noble gas core. In chemical reactions, lanthanum almost always gives up these three valence electrons from the 5d and 6s subshells to form the +3 oxidation state, achieving the stable configuration of the preceding noble gas xenon. [14] Some lanthanum(II) compounds are also known, but they are usually much less stable. [15] [16] Lanthanum Monoxide (LaO) produces strong absorption bands in some stellar spectra. [17]

Among the lanthanides, lanthanum is exceptional as it has no 4f electrons as a single gas-phase atom. Thus it is only very weakly paramagnetic, unlike the strongly paramagnetic later lanthanides (with the exceptions of the last two, ytterbium and lutetium, where the 4f shell is completely full). [18] However, the 4f shell of lanthanum can become partially occupied in chemical environments and participate in chemical bonding. [19] [20] For example, the melting points of the trivalent lanthanides (all but europium and ytterbium) are related to the extent of hybridisation of the 6s, 5d, and 4f electrons (lowering with increasing 4f involvement), [21] and lanthanum has the second-lowest melting point among them: 920 °C. (Europium and ytterbium have lower melting points because they delocalise about two electrons per atom rather than three.) [22] This chemical availability of f orbitals justifies lanthanum's placement in the f-block despite its anomalous ground-state configuration [23] [24] (which is merely the result of strong interelectronic repulsion making it less profitable to occupy the 4f shell, as it is small and close to the core electrons). [25]

The lanthanides become harder as the series is traversed: as expected, lanthanum is a soft metal. Lanthanum has a relatively high resistivity of 615 nΩm at room temperature; in comparison, the value for the good conductor aluminium is only 26.50 nΩm. [26] [27] Lanthanum is the least volatile of the lanthanides. [28] Like most of the lanthanides, lanthanum has a hexagonal crystal structure at room temperature. At 310 °C, lanthanum changes to a face-centered cubic structure, and at 865 °C, it changes to a body-centered cubic structure. [27]

Chemical

As expected from periodic trends, lanthanum has the largest atomic radius of the lanthanides. Hence, it is the most reactive among them, tarnishing quite rapidly in air, turning completely dark after several hours and can readily burn to form lanthanum(III) oxide, La2O3, which is almost as basic as calcium oxide. [29] A centimeter-sized sample of lanthanum will corrode completely in a year as its oxide spalls off like iron rust, instead of forming a protective oxide coating like aluminium, scandium, yttrium, and lutetium. [30] Lanthanum reacts with the halogens at room temperature to form the trihalides, and upon warming will form binary compounds with the nonmetals nitrogen, carbon, sulfur, phosphorus, boron, selenium, silicon and arsenic. [14] [15] Lanthanum reacts slowly with water to form lanthanum(III) hydroxide, La(OH)3. [31] In dilute sulfuric acid, lanthanum readily forms the aquated tripositive ion [La(H2O)9]3+: this is colorless in aqueous solution since La3+ has no d or f electrons. [31] Lanthanum is the strongest and hardest base among the rare earth elements, which is again expected from its being the largest of them. [32]

Some lanthanum(II) compounds are also known, but they are much less stable. [15] Therefore, in officially naming compounds of lanthanum its oxidation number always is to be mentioned.

Isotopes

Excerpt from the chart of nuclides showing stable isotopes (black) from barium (Z = 56) to neodymium (Z = 60) Lanthanum stable nucleus.png
Excerpt from the chart of nuclides showing stable isotopes (black) from barium (Z = 56) to neodymium (Z = 60)

Naturally occurring lanthanum is made up of two isotopes, the stable 139La and the primordial long-lived radioisotope 138La. 139La is by far the most abundant, making up 99.910% of natural lanthanum: it is produced in the s-process (slow neutron capture, which occurs in low- to medium-mass stars) and the r-process (rapid neutron capture, which occurs in core-collapse supernovae). It is the only stable isotope of lanthanum. [33] The very rare isotope 138La is one of the few primordial odd–odd nuclei, with a long half-life of 1.05×1011 years. It is one of the proton-rich p-nuclei which cannot be produced in the s- or r-processes. 138La, along with the even rarer 180mTa, is produced in the ν-process, where neutrinos interact with stable nuclei. [34] All other lanthanum isotopes are synthetic: with the exception of 137La with a half-life of about 60,000 years, all of them have half-lives less than two days, and most have half-lives less than a minute. The isotopes 139La and 140La occur as fission products of uranium. [33]

Compounds

Lanthanum oxide is a white solid that can be prepared by direct reaction of its constituent elements. Due to the large size of the La3+ ion, La2O3 adopts a hexagonal 7-coordinate structure that changes to the 6-coordinate structure of scandium oxide (Sc2O3) and yttrium oxide (Y2O3) at high temperature. When it reacts with water, lanthanum hydroxide is formed: [35] a lot of heat is evolved in the reaction and a hissing sound is heard. Lanthanum hydroxide will react with atmospheric carbon dioxide to form the basic carbonate. [36]

Lanthanum fluoride is insoluble in water and can be used as a qualitative test for the presence of La3+. The heavier halides are all very soluble deliquescent compounds. The anhydrous halides are produced by direct reaction of their elements, as heating the hydrates causes hydrolysis: for example, heating hydrated LaCl3 produces LaOCl. [36]

Lanthanum reacts exothermically with hydrogen to produce the dihydride LaH2, a black, pyrophoric, brittle, conducting compound with the calcium fluoride structure. [37] This is a non-stoichiometric compound, and further absorption of hydrogen is possible, with a concomitant loss of electrical conductivity, until the more salt-like LaH3 is reached. [36] Like LaI2 and LaI, LaH2 is probably an electride compound. [36]

Due to the large ionic radius and great electropositivity of La3+, there is not much covalent contribution to its bonding and hence it has a limited coordination chemistry, like yttrium and the other lanthanides. [38] Lanthanum oxalate does not dissolve very much in alkali-metal oxalate solutions, and [La(acac)3(H2O)2] decomposes around 500 °C. Oxygen is the most common donor atom in lanthanum complexes, which are mostly ionic and often have high coordination numbers over 6: 8 is the most characteristic, forming square antiprismatic and dodecadeltahedral structures. These high-coordinate species, reaching up to coordination number 12 with the use of chelating ligands such as in La2(SO4)3·9H2O, often have a low degree of symmetry because of stereo-chemical factors. [38]

Lanthanum chemistry tends not to involve π bonding due to the electron configuration of the element: thus its organometallic chemistry is quite limited. The best characterized organolanthanum compounds are the cyclopentadienyl complex La(C5H5)3, which is produced by reacting anhydrous LaCl3 with NaC5H5 in tetrahydrofuran, and its methyl-substituted derivatives. [39]

History

Carl Gustaf Mosander, the scientist who discovered lanthanum as well as terbium and erbium Mosander Carl Gustav bw.jpg
Carl Gustaf Mosander, the scientist who discovered lanthanum as well as terbium and erbium

In 1751, the Swedish mineralogist Axel Fredrik Cronstedt discovered a heavy mineral from the mine at Bastnäs, later named cerite. Thirty years later, the fifteen-year-old Wilhelm Hisinger, from the family owning the mine, sent a sample of it to Carl Scheele, who did not find any new elements within. In 1803, after Hisinger had become an ironmaster, he returned to the mineral with Jöns Jacob Berzelius and isolated a new oxide which they named ceria after the dwarf planet Ceres, which had been discovered two years earlier. [40] Ceria was simultaneously independently isolated in Germany by Martin Heinrich Klaproth. [41] Between 1839 and 1843, ceria was shown to be a mixture of oxides by the Swedish surgeon and chemist Carl Gustaf Mosander, who lived in the same house as Berzelius and studied under him: he separated out two other oxides which he named lanthana and didymia . [42] [43] He partially decomposed a sample of cerium nitrate by roasting it in air and then treating the resulting oxide with dilute nitric acid. [44] That same year, Axel Erdmann, a student also at the Karolinska Institute, discovered lanthanum in a new mineral from Låven island located in a Norwegian fjord.

Finally, Mosander explained his delay, saying that he had extracted a second element from cerium, and this he called didymium. Although he didn't realise it, didymium too was a mixture, and in 1885 it was separated into praseodymium and neodymium.

Since lanthanum's properties differed only slightly from those of cerium, and occurred along with it in its salts, he named it from the Ancient Greek λανθάνειν [lanthanein] (lit. to lie hidden). [41] Relatively pure lanthanum metal was first isolated in 1923. [15]

Occurrence and production

Lanthanum is the third-most abundant of all the lanthanides, making up 39 mg/kg of the Earth's crust, behind neodymium at 41.5 mg/kg and cerium at 66.5 mg/kg. It is almost three times as abundant as lead in the Earth's crust. [45] Despite being among the so-called "rare earth metals", lanthanum is thus not rare at all, but it is historically so named because it is rarer than "common earths" such as lime and magnesia, and historically only a few deposits were known. Lanthanum is considered a rare earth metal because the process to mine it is difficult, time-consuming, and expensive. [15] Lanthanum is rarely the dominant lanthanide found in the rare earth minerals, and in their chemical formulae it is usually preceded by cerium. Rare examples of La-dominant minerals are monazite-(La) and lanthanite-(La). [46]

Production of Lanthanum from Monazite sand Monazite acid cracking process.svg
Production of Lanthanum from Monazite sand

The La3+ ion is similarly sized to the early lanthanides of the cerium group (those up to samarium and europium) that immediately follow in the periodic table, and hence it tends to occur along with them in phosphate, silicate and carbonate minerals, such as monazite (MIIIPO4) and bastnäsite (MIIICO3F), where M refers to all the rare earth metals except scandium and the radioactive promethium (mostly Ce, La, and Y). [47] Bastnäsite is usually lacking in thorium and the heavy lanthanides, and the purification of the light lanthanides from it is less involved. The ore, after being crushed and ground, is first treated with hot concentrated sulfuric acid, evolving carbon dioxide, hydrogen fluoride, and silicon tetrafluoride: the product is then dried and leached with water, leaving the early lanthanide ions, including lanthanum, in solution. [48]

The procedure for monazite, which usually contains all the rare earths as well as thorium, is more involved. Monazite, because of its magnetic properties, can be separated by repeated electromagnetic separation. After separation, it is treated with hot concentrated sulfuric acid to produce water-soluble sulfates of rare earths. The acidic filtrates are partially neutralized with sodium hydroxide to pH 3–4. Thorium precipitates out of solution as hydroxide and is removed. After that, the solution is treated with ammonium oxalate to convert rare earths to their insoluble oxalates. The oxalates are converted to oxides by annealing. The oxides are dissolved in nitric acid that excludes one of the main components, cerium, whose oxide is insoluble in HNO3. Lanthanum is separated as a double salt with ammonium nitrate by crystallization. This salt is relatively less soluble than other rare earth double salts and therefore stays in the residue. [15] Care must be taken when handling some of the residues as they contain 228Ra, the daughter of 232Th, which is a strong gamma emitter. [48] Lanthanum is relatively easy to extract as it has only one neighbouring lanthanide, cerium, which can be removed by making use of its ability to be oxidised to the +4 state; thereafter, lanthanum may be separated out by the historical method of fractional crystallization of La(NO3)3·2NH4NO3·4H2O, or by ion-exchange techniques when higher purity is desired. [48]

Lanthanum metal is obtained from its oxide by heating it with ammonium chloride or fluoride and hydrofluoric acid at 300-400 °C to produce the chloride or fluoride: [15]

La2O3 + 6 NH4Cl → 2 LaCl3 + 6 NH3 + 3 H2O

This is followed by reduction with alkali or alkaline earth metals in vacuum or argon atmosphere: [15]

LaCl3 + 3 Li → La + 3 LiCl

Also, pure lanthanum can be produced by electrolysis of molten mixture of anhydrous LaCl3 and NaCl or KCl at elevated temperatures. [15]

Applications

A Coleman white gas lantern mantle burning at full brightness Glowing gas mantle.jpg
A Coleman white gas lantern mantle burning at full brightness

The first historical application of lanthanum was in gas lantern mantles. Carl Auer von Welsbach used a mixture of lanthanum oxide and zirconium oxide, which he called Actinophor and patented in 1886. The original mantles gave a green-tinted light and were not very successful, and his first company, which established a factory in Atzgersdorf in 1887, failed in 1889. [49]

Modern uses of lanthanum include:

LaB
6 hot cathode LaB6HotCathode.jpg
LaB
6
hot cathode
Comparison of infrared transmittance of ZBLAN glass and silica Zblan transmit.jpg
Comparison of infrared transmittance of ZBLAN glass and silica

Biological role

Lanthanum has no known biological role in humans. The element is very poorly absorbed after oral administration and when injected its elimination is very slow. Lanthanum carbonate (Fosrenol) was approved as a phosphate binder to absorb excess phosphate in cases of end stage renal disease. [67]

While lanthanum has pharmacological effects on several receptors and ion channels, its specificity for the GABA receptor is unique among trivalent cations. Lanthanum acts at the same modulatory site on the GABA receptor as zinc, a known negative allosteric modulator. The lanthanum cation La3+ is a positive allosteric modulator at native and recombinant GABA receptors, increasing open channel time and decreasing desensitization in a subunit configuration dependent manner. [71]

Lanthanum is an essential cofactor for the methanol dehydrogenase of the methanotrophic bacterium Methylacidiphilum fumariolicum SolV, although the great chemical similarity of the lanthanides means that it may be substituted with cerium, praseodymium, or neodymium without ill effects, and with the smaller samarium, europium, or gadolinium giving no side effects other than slower growth. [72]

Precautions

Lanthanum
Hazards
GHS labelling:
GHS-pictogram-flamme.svg
Danger
H260
P223, P231+P232, P370+P378, P422 [73]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
0
4
2
W

Lanthanum has a low to moderate level of toxicity and should be handled with care. The injection of lanthanum solutions produces hyperglycemia, low blood pressure, degeneration of the spleen and hepatic alterations.[ citation needed ] The application in carbon arc light led to the exposure of people to rare earth element oxides and fluorides, which sometimes led to pneumoconiosis. [74] [75] As the La3+ ion is similar in size to the Ca2+ ion, it is sometimes used as an easily traced substitute for the latter in medical studies. [76] Lanthanum, like the other lanthanides, is known to affect human metabolism, lowering cholesterol levels, blood pressure, appetite, and risk of blood coagulation. When injected into the brain, it acts as a painkiller, similarly to morphine and other opiates, though the mechanism behind this is still unknown. [76] Lanthanum meant for ingestion, typically as a chewable tablet or oral powder, can interfere with gastrointestinal imaging by creating opacities throughout the GI tract; if chewable tablets are swallowed whole, they will dissolve but present initially as coin-shaped opacities in the stomach, potentially confused with ingested metal objects such as coins or batteries. [77]

Prices

The price for a (metric) ton [1000 kg] of Lanthanum oxide 99% (FOB China in USD/Mt) is given by the Institute of Rare Earths Elements and Strategic Metals as below $2,000 for most of the period from early 2001 to September 2010 (at $10,000 in the short term in 2008); it rose steeply to $140,000 in mid-2011 and fell back just as rapidly to $38,000 by early 2012. [78] The average price for the last six months (April to September 2022) is given by the Institute as follows: Lanthanum Oxide - 99.9%min FOB China - 1308 EUR/mt and for Lanthanum Metal - 99%min FOB China - 3706 EUR/mt. [79]

See also

| CASNo_Ref =  Yes check.svgY | CASNo = 7439–91–0 | UNII_Ref =  Yes check.svgY | UNII = 6I3K30563S

Related Research Articles

<span class="mw-page-title-main">Europium</span> Chemical element, symbol Eu and atomic number 63

Europium is a chemical element; it has symbol Eu and atomic number 63. Europium is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating. It is the most chemically reactive, least dense, and softest of the lanthanide elements. It is soft enough to be cut with a knife. Europium was isolated in 1901 and named after the continent of Europe. Europium usually assumes the oxidation state +3, like other members of the lanthanide series, but compounds having oxidation state +2 are also common. All europium compounds with oxidation state +2 are slightly reducing. Europium has no significant biological role and is relatively non-toxic compared to other heavy metals. Most applications of europium exploit the phosphorescence of europium compounds. Europium is one of the rarest of the rare-earth elements on Earth.

<span class="mw-page-title-main">Erbium</span> Chemical element, symbol Er and atomic number 68

Erbium is a chemical element; it has symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare-earth element, originally found in the gadolinite mine in Ytterby, Sweden, which is the source of the element's name.

<span class="mw-page-title-main">Holmium</span> Chemical element, symbol Ho and atomic number 67

Holmium is a chemical element; it has symbol Ho and atomic number 67. It is a rare-earth element and the eleventh member of the lanthanide series. It is a relatively soft, silvery, fairly corrosion-resistant and malleable metal. Like many other lanthanides, holmium is too reactive to be found in native form, as pure holmium slowly forms a yellowish oxide coating when exposed to air. When isolated, holmium is relatively stable in dry air at room temperature. However, it reacts with water and corrodes readily, and also burns in air when heated.

<span class="mw-page-title-main">Lutetium</span> Chemical element, symbol Lu and atomic number 71

Lutetium is a chemical element; it has symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earth elements; it can also be classified as the first element of the 6th-period transition metals.

The lanthanide or lanthanoid series of chemical elements comprises at least the 14 metallic chemical elements with atomic numbers 57–70, from lanthanum through ytterbium. In the periodic table, they fill the 4f orbitals. Lutetium is also sometimes considered a lanthanide, despite being a d-block element and a transition metal.

<span class="mw-page-title-main">Neodymium</span> Chemical element, symbol Nd and atomic number 60

Neodymium is a chemical element; it has symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly producing pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states. It is generally regarded as having one of the most complex spectra of the elements. Neodymium was discovered in 1885 by the Austrian chemist Carl Auer von Welsbach, who also discovered praseodymium. It is present in significant quantities in the minerals monazite and bastnäsite. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Neodymium is fairly common—about as common as cobalt, nickel, or copper and is widely distributed in the Earth's crust. Most of the world's commercial neodymium is mined in China, as is the case with many other rare-earth metals.

<span class="mw-page-title-main">Periodic table</span> Tabular arrangement of the chemical elements ordered by atomic number

The periodic table, also known as the periodic table of the elements, arranges the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which says that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the same group tend to show similar chemical characteristics.

<span class="mw-page-title-main">Terbium</span> Chemical element, symbol Tb and atomic number 65

Terbium is a chemical element; it has symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, and ductile. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.

<span class="mw-page-title-main">Thulium</span> Chemical element, symbol Tm and atomic number 69

Thulium is a chemical element; it has symbol Tm and atomic number 69. It is the thirteenth and third-last element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds; however, the +2 oxidation state can also be stable. In aqueous solution, like compounds of other late lanthanides, soluble thulium compounds form coordination complexes with nine water molecules.

In chemistry, a transition metal is a chemical element in the d-block of the periodic table, though the elements of group 12 are sometimes excluded. The lanthanide and actinide elements are called inner transition metals and are sometimes considered to be transition metals as well.

<span class="mw-page-title-main">Mischmetal</span> Pyrophoric rare-earth metal alloy

Mischmetal (from German: Mischmetall – "mixed metal") is an alloy of rare-earth elements. It is also called cerium mischmetal, or rare-earth mischmetal. A typical composition includes approximately 55% cerium, 25% lanthanum, and 15~18% neodymium, with traces of other rare earth metals; it contains 95% lanthanides and 5% iron. Its most common use is in the pyrophoric ferrocerium "flint" ignition device of many lighters and torches, although an alloy of only rare-earth elements would be too soft to give good sparks. For this purpose, it is blended with iron oxide and magnesium oxide to form a harder material known as ferrocerium. In chemical formulae it is commonly abbreviated as Mm, e.g. MmNi5.

<span class="mw-page-title-main">Monazite</span> Mineral containing rare-earth elements

Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the cerium-dominant member of the group. It occurs usually in small isolated crystals. It has a hardness of 5.0 to 5.5 on the Mohs scale of mineral hardness and is relatively dense, about 4.6 to 5.7 g/cm3. There are five different most common species of monazite, depending on the relative amounts of the rare earth elements in the mineral:

<span class="mw-page-title-main">Praseodymium</span> Chemical element, symbol Pr and atomic number 59

Praseodymium is a chemical element; it has symbol Pr and the atomic number 59. It is the third member of the lanthanide series and is considered one of the rare-earth metals. It is a soft, silvery, malleable and ductile metal, valued for its magnetic, electrical, chemical, and optical properties. It is too reactive to be found in native form, and pure praseodymium metal slowly develops a green oxide coating when exposed to air.

<span class="mw-page-title-main">Group 3 element</span> Group of chemical elements

Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare-earth elements. It contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). The group is also called the scandium group or scandium family after its lightest member.

<span class="mw-page-title-main">Lanthanum oxide</span> Chemical compound

Lanthanum(III) oxide, also known as lanthana, chemical formula La2O3, is an inorganic compound containing the rare earth element lanthanum and oxygen. It is used in some ferroelectric materials, as a component of optical materials, and is a feedstock for certain catalysts, among other uses.

<span class="mw-page-title-main">Yttrium</span> Chemical element, symbol Y and atomic number 39

Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89Y is the only stable isotope and the only isotope found in the Earth's crust.

<span class="mw-page-title-main">Cerium</span> Chemical element, symbol Ce and atomic number 58

Cerium is a chemical element; it has symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the oxidation state of +3 characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements. Cerium has no known biological role in humans but is not particularly toxic, except with intense or continued exposure.

Scandium compounds are compounds containing the element scandium. The chemistry of scandium is almost completely dominated by the trivalent ion, Sc3+, due to its electron configuration, [Ar] 3d14s2. The radii of M3+ ions in the table below indicate that the chemical properties of scandium ions have more in common with yttrium ions than with aluminium ions. In part because of this similarity, scandium is often classified as a lanthanide-like element.

Praseodymium compounds are compounds formed by the lanthanide metal praseodymium (Pr). In these compounds, praseodymium generally exhibits the +3 oxidation state, such as PrCl3, Pr(NO3)3 and Pr(CH3COO)3. However, compounds with praseodymium in the +2 and +4 oxidation states, and unlike other lanthanides, the +5 oxidation state, are also known.

Cerium compounds are compounds containing the element cerium (Ce), a lanthanide. Cerium exists in two main oxidation states, Ce(III) and Ce(IV). This pair of adjacent oxidation states dominates several aspects of the chemistry of this element. Cerium(IV) aqueous solutions may be prepared by reacting cerium(III) solutions with the strong oxidizing agents peroxodisulfate or bismuthate. The value of E(Ce4+/Ce3+) varies widely depending on conditions due to the relative ease of complexation and hydrolysis with various anions, although +1.72 V is representative. Cerium is the only lanthanide which has important aqueous and coordination chemistry in the +4 oxidation state.

References

  1. "Standard Atomic Weights: Lanthanum". CIAAW. 2005.
  2. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  3. Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017. and Arnold, Polly L.; Petrukhina, Marina A.; Bochenkov, Vladimir E.; Shabatina, Tatyana I.; Zagorskii, Vyacheslav V.; Cloke (2003-12-15). "Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation". Journal of Organometallic Chemistry. 688 (1–2): 49–55. doi:10.1016/j.jorganchem.2003.08.028.
  4. La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB8 clusters; see Li, Wan-Lu; Chen, Teng-Teng; Chen, Wei-Jia; Li, Jun; Wang, Lai-Sheng (2021). "Monovalent lanthanide(I) in borozene complexes". Nature Communications. 12 (1): 6467. doi:10.1038/s41467-021-26785-9. PMC   8578558 . PMID   34753931.
  5. Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN   0-8493-0486-5.
  6. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN   0-8493-0464-4.
  7. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  8. "Monazite-(Ce) Mineral Data". Webmineral. Retrieved 10 July 2016.
  9. Fluck, E. (1988). "New Notations in the Periodic Table" (PDF). Pure Appl. Chem. 60 (3): 431–36. doi:10.1351/pac198860030431. S2CID   96704008. Archived (PDF) from the original on 25 March 2012. Retrieved 24 March 2012.
  10. L. D. Landau, E. M. Lifshitz (1958). Quantum Mechanics: Non-Relativistic Theory. Vol. 3 (1st ed.). Pergamon Press. pp. 256–7.
  11. William B. Jensen (1982). "The Positions of Lanthanum (Actinium) and Lutetium (Lawrencium) in the Periodic Table". J. Chem. Educ. 59 (8): 634–636. Bibcode:1982JChEd..59..634J. doi:10.1021/ed059p634.
  12. Jensen, William B. (2015). "The positions of lanthanum (actinium) and lutetium (lawrencium) in the periodic table: an update". Foundations of Chemistry. 17: 23–31. doi:10.1007/s10698-015-9216-1. S2CID   98624395 . Retrieved 28 January 2021.
  13. Scerri, Eric (18 January 2021). "Provisional Report on Discussions on Group 3 of the Periodic Table". Chemistry International. 43 (1): 31–34. doi: 10.1515/ci-2021-0115 . S2CID   231694898.
  14. 1 2 Greenwood and Earnshaw, p. 1106
  15. 1 2 3 4 5 6 7 8 9 10 Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. pp. 444–446. ISBN   978-0-07-049439-8 . Retrieved 2009-06-06.
  16. Hitchcock, Peter B.; Lappert, Michael F.; Maron, Laurent; Protchenko, Andrey V. (2008). "Lanthanum Does Form Stable Molecular Compounds in the +2 Oxidation State". Angewandte Chemie. 120 (8): 1510. Bibcode:2008AngCh.120.1510H. doi:10.1002/ange.200704887.
  17. Jevons, W. (1928). "The band spectrum of lanthanum monoxide". Proceedings of the Physical Society. 41 (1): 520. Bibcode:1928PPS....41..520J. doi:10.1088/0959-5309/41/1/355.
  18. Cullity, B. D. and Graham, C. D. (2011) Introduction to Magnetic Materials, John Wiley & Sons, ISBN   9781118211496
  19. Wittig, Jörg (1973). "The pressure variable in solid state physics: What about 4f-band superconductors?". In H. J. Queisser (ed.). Festkörper Probleme: Plenary Lectures of the Divisions Semiconductor Physics, Surface Physics, Low Temperature Physics, High Polymers, Thermodynamics and Statistical Mechanics, of the German Physical Society, Münster, March 19–24, 1973. Advances in Solid State Physics. Vol. 13. Berlin, Heidelberg: Springer. pp. 375–396. doi:10.1007/BFb0108579. ISBN   978-3-528-08019-8.
  20. Krinsky, Jamin L.; Minasian, Stefan G.; Arnold, John (2010-12-08). "Covalent Lanthanide Chemistry Near the Limit of Weak Bonding: Observation of (CpSiMe3)3Ce−ECp* and a Comprehensive Density Functional Theory Analysis of Cp3Ln−ECp (E = Al, Ga)". Inorganic Chemistry. American Chemical Society (ACS). 50 (1): 345–357. doi:10.1021/ic102028d. ISSN   0020-1669.
  21. Gschneidner, Karl A. Jr. (2016). "282. Systematics". In Jean-Claude G. Bünzli; Vitalij K. Pecharsky (eds.). Handbook on the Physics and Chemistry of Rare Earths. Vol. 50. pp. 12–16. ISBN   978-0-444-63851-9.
  22. Krishnamurthy, Nagaiyar and Gupta, Chiranjib Kumar (2004) Extractive Metallurgy of Rare Earths, CRC Press, ISBN   0-415-33340-7
  23. Hamilton, David C. (1965). "Position of Lanthanum in the Periodic Table". American Journal of Physics. 33 (8): 637–640. Bibcode:1965AmJPh..33..637H. doi:10.1119/1.1972042.
  24. Jensen, W. B. (2015). "Some Comments on the Position of Lawrencium in the Periodic Table" (PDF). Archived from the original (PDF) on 23 December 2015. Retrieved 20 September 2015.
  25. Jørgensen, Christian (1973). "The Loose Connection between Electron Configuration and the Chemical Behavior of the Heavy Elements (Transuranics)". Angewandte Chemie International Edition. 12 (1): 12–19. doi:10.1002/anie.197300121.
  26. Greenwood and Earnshaw, p. 1429
  27. 1 2 3 4 5 6 Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN   0-8493-0486-5.
  28. "The Radiochemistry of the Rare Earths, Scandium, Yttrium, and Actinium" (PDF). Archived (PDF) from the original on 2021-08-31. Retrieved 2016-06-23.
  29. Greenwood and Earnshaw, p. 1105–7
  30. "Rare-Earth Metal Long Term Air Exposure Test" . Retrieved 2009-08-08.
  31. 1 2 "Chemical reactions of Lanthanum". Webelements. Retrieved 2009-06-06.
  32. Greenwood and Earnshaw, p. 1434
  33. 1 2 Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (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
  34. Woosley, S. E.; Hartmann, D. H.; Hoffman, R. D.; Haxton, W. C. (1990). "The ν-process". The Astrophysical Journal. 356: 272–301. Bibcode:1990ApJ...356..272W. doi:10.1086/168839.
  35. E.V. Shkolnikov (2009). "Thermodynamic Characterization of the Amphoterism of Hydroxides and Oxides of Scandium Subgroup Elements in Aqueous Media". Russian Journal of Applied Chemistry. 82 (2): 2098–2104. doi:10.1134/S1070427209120040. S2CID   93220420.
  36. 1 2 3 4 Greenwood and Earnshaw, p. 1107–8
  37. Fukai, Y. (2005). The Metal-Hydrogen System, Basic Bulk Properties, 2d edition. Springer. ISBN   978-3-540-00494-3.
  38. 1 2 Greenwood and Earnshaw, pp. 1108–9
  39. Greenwood and Earnshaw, p. 1110
  40. "The Discovery and Naming of the Rare Earths". Elements.vanderkrogt.net. Retrieved 23 June 2016.
  41. 1 2 Greenwood and Earnshaw, p. 1424
  42. Weeks, Mary Elvira (1956). The discovery of the elements (6th ed.). Easton, PA: Journal of Chemical Education.
  43. Weeks, Mary Elvira (1932). "The Discovery of the Elements: XI. Some Elements Isolated with the Aid of Potassium and Sodium:Zirconium, Titanium, Cerium and Thorium". The Journal of Chemical Education. 9 (7): 1231–1243. Bibcode:1932JChEd...9.1231W. doi:10.1021/ed009p1231.
  44. See:
    • (Berzelius) (1839) "Nouveau métal" (New metal), Comptes rendus, 8 : 356-357. From p. 356: "L'oxide de cérium, extrait de la cérite par la procédé ordinaire, contient à peu près les deux cinquièmes de son poids de l'oxide du nouveau métal qui ne change que peu les propriétés du cérium, et qui s'y tient pour ainsi dire caché. Cette raison a engagé M. Mosander à donner au nouveau métal le nom de Lantane." (The oxide of cerium, extracted from cerite by the usual procedure, contains almost two fifths of its weight in the oxide of the new metal, which differs only slightly from the properties of cerium, and which is held in it so to speak "hidden". This reason motivated Mr. Mosander to give to the new metal the name Lantane.)
    • (Berzelius) (1839) "Latanium — a new metal," Archived 2022-11-15 at the Wayback Machine Philosophical Magazine, new series, 14 : 390-391.
  45. "It's Elemental — The Periodic Table of Elements". Jefferson Lab. Archived from the original on 29 April 2007. Retrieved 2007-04-14.
  46. Hudson Institute of Mineralogy (1993–2018). "Mindat.org". www.mindat.org. Retrieved 14 January 2018.
  47. Greenwood and Earnshaw, p. 1103
  48. 1 2 3 Greenwood and Earnshaw, p. 1426–9
  49. Evans, C. H., ed. (2012-12-06). Episodes from the History of the Rare Earth Elements. Kluwer Academic Publishers. p. 122. ISBN   9789400902879.
  50. "Inside the Nickel Metal Hydride Battery" (PDF). Archived from the original (PDF) on 2009-02-27. Retrieved 2009-06-06.
  51. Tliha, M.; Mathlouthi, H.; Lamloumi, J.; Percheronguegan, A. (2007). "AB5-type hydrogen storage alloy used as anodic materials in Ni-MH batteries". Journal of Alloys and Compounds. 436 (1–2): 221–225. doi:10.1016/j.jallcom.2006.07.012.
  52. "As hybrid cars gobble rare metals, shortage looms". Reuters 2009-08-31. 2009-08-31.
  53. Bauerlein, P.; Antonius, C.; Loffler, J.; Kumpers, J. (2008). "Progress in high-power nickel–metal hydride batteries". Journal of Power Sources. 176 (2): 547. Bibcode:2008JPS...176..547B. doi:10.1016/j.jpowsour.2007.08.052.
  54. "Why Toyota offers 2 battery choices in next Prius". 19 November 2015.
  55. Uchida, H. (1999). "Hydrogen solubility in rare earth based hydrogen storage alloys". International Journal of Hydrogen Energy. 24 (9): 871–877. doi:10.1016/S0360-3199(98)00161-X.
  56. C. R. Hammond (2000). The Elements, in Handbook of Chemistry and Physics (81st ed.). CRC press. ISBN   978-0-8493-0481-1.
  57. Jason D. Sommerville & Lyon B. King. "Effect of Cathode Position on Hall-Effect Thruster Performance and Cathode Coupling Voltage" (PDF). 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 8–11 July 2007, Cincinnati, OH. Archived from the original (PDF) on July 20, 2011. Retrieved 2009-06-06.
  58. Harrington, James A. "Infrared Fiber Optics" (PDF). Rutgers University. Archived from the original (PDF) on 2010-08-02.
  59. "BrilLanCe-NxGen" (PDF). Archived from the original (PDF) on 2011-04-29. Retrieved 2009-06-06.
  60. Hendrick, James B. (1985). "Rare Earth Elements and Yttrium". Mineral Facts and Problems (Report). Bureau of Mines. p. 655. Bulletin 675.
  61. Kim, K; Shim, Kwang Bo (2003). "The effect of lanthanum on the fabrication of ZrB2–ZrC composites by spark plasma sintering". Materials Characterization. 50: 31–37. doi:10.1016/S1044-5803(03)00055-X.
  62. Pool Care Basics. pp. 25–26.
  63. Howard B. Cary (1995). Arc welding automation. CRC Press. p. 139. ISBN   978-0-8247-9645-7.
  64. Larry Jeffus. (2003). "Types of Tungsten". Welding : principles and applications. Clifton Park, N.Y.: Thomson/Delmar Learning. p. 350. ISBN   978-1-4018-1046-7. Archived from the original on 2010-09-23.
  65. C. K. Gupta; Nagaiyar Krishnamurthy (2004). Extractive metallurgy of rare earths. CRC Press. p. 441. ISBN   978-0-415-33340-5.
  66. S. Nakai; A. Masuda; B. Lehmann (1988). "La-Ba dating of bastnaesite" (PDF). American Mineralogist. 7 (1–2): 1111. Bibcode:1988ChGeo..70...12N. doi:10.1016/0009-2541(88)90211-2.
  67. 1 2 "FDA approves Fosrenol(R) in end-stage renal disease (ESRD) patients". 28 October 2004. Archived from the original on 2009-04-26. Retrieved 2009-06-06.
  68. Chau YP; Lu KS (1995). "Investigation of the blood-ganglion barrier properties in rat sympathetic ganglia by using lanthanum ion and horseradish peroxidase as tracers". Acta Anatomica. 153 (2): 135–144. doi:10.1159/000313647. ISSN   0001-5180. PMID   8560966.
  69. Hagheseresht; Wang, Shaobin; Do, D. D. (2009). "A novel lanthanum-modified bentonite, Phoslock, for phosphate removal from wastewaters". Applied Clay Science. 46 (4): 369–375. Bibcode:2009ApCS...46..369H. doi:10.1016/j.clay.2009.09.009.
  70. R. Smith, Michael B.; Whiting, Christopher; Barklay, Chad (2019). "Nuclear Considerations for the Application of Lanthanum Telluride in Future Radioisotope Power Systems". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742136. ISBN   978-1-5386-6854-2. OSTI   1542236. S2CID   195221607.
  71. Boldyreva, A. A. (2005). "Lanthanum Potentiates GABA-Activated Currents in Rat Pyramidal Neurons of CA1 Hippocampal Field". Bulletin of Experimental Biology and Medicine. 140 (4): 403–5. doi:10.1007/s10517-005-0503-z. PMID   16671565. S2CID   13179025.
  72. Pol, Arjan; Barends, Thomas R. M.; Dietl, Andreas; Khadem, Ahmad F.; Eygensteyn, Jelle; Jetten, Mike S. M.; Op Den Camp, Huub J. M. (2013). "Rare earth metals are essential for methanotrophic life in volcanic mudpots" (PDF). Environmental Microbiology. 16 (1): 255–64. doi:10.1111/1462-2920.12249. PMID   24034209.
  73. "Lanthanum 261130". Sigma-Aldrich.
  74. Dufresne, A.; Krier, G.; Muller, J.; Case, B.; Perrault, G. (1994). "Lanthanide particles in the lung of a printer". Science of the Total Environment. 151 (3): 249–252. Bibcode:1994ScTEn.151..249D. doi:10.1016/0048-9697(94)90474-X. PMID   8085148.
  75. Waring, P. M.; Watling, R. J. (1990). "Rare earth deposits in a deceased movie projectionist. A new case of rare earth pneumoconiosis". The Medical Journal of Australia. 153 (11–12): 726–30. doi:10.5694/j.1326-5377.1990.tb126334.x. PMID   2247001. S2CID   24985591.
  76. 1 2 Emsley, John (2011). Nature's building blocks: an A-Z guide to the elements. Oxford University Press. pp. 266–77. ISBN   9780199605637.
  77. Evans NS, Aronowitz P, Altertson TE (October 30, 2023). "Coin-Shaped Opacities in the Stomach". JAMA Clinical Challenge. JAMA . 330 (20): 2016–2017. doi:10.1001/jama.2023.19032. PMID   37902730. S2CID   264589220.
  78. Specifications and notation: "lanthanum"..access-date=27 October 2022.
  79. Information and notation: "ISE Metal-quotes"..access-date=27 October 2022.

Bibliography

Further reading