Lanthanum (La)
lanthanideSolid
प्रमाणित अणुभार
138.90547 uइलेक्ट्रॉन संरूपण
[Xe] 6s2 5d1द्रवणांक
917.85 °Cउत्कलनांक
3463.85 °Cघनता
6150 kg/m³ऑक्सिडीकरण अवस्था
0, +1, +2, +3विद्युतऋणता (पॉलिंग)
1.1आयनीकरण ऊर्जा (पहिली)
5.5769 eVशोधाचे वर्ष
1839अणुत्रिज्या
195 pmतपशील
Lanthanum is the first element of the lanthanide series by common convention, although its 4f shell is empty in the neutral atom. It is a soft, reactive rare-earth metal that occurs with other light rare earths in minerals such as monazite and bastnäsite. Its chemistry is dominated by the large La³⁺ ion, which gives mostly colorless, strongly ionic compounds. Lanthanum is important in optical glass, catalysts, battery alloys, and high-temperature ceramic materials.
Lanthanum is silvery white, malleable, ductile, and soft enough to be cut with a knife. It is one of the most reactive of the rare-earth metals. It oxidizes rapidly when exposed to air. Cold water attacks lanthanum slowly, while hot water attacks it much more rapidly.
The metal reacts directly with elemental carbon, nitrogen, boron, selenium, silicon, phosphorus, sulfur, and with halogens.
At 310°C, lanthanum changes from a hexagonal to a face-centered cubic structure, and at 865°C it again transforms into a body-centered cubic structure.
The name derives from the Greek lanthanein for "to be hidden" or "to escape notice" because it hid in cerium ore and was difficult to separate from that rare earth mineral. Lanthanum was discovered by the Swedish surgeon and chemist Carl-Gustav Mosander in 1839. In 1842, Mosander separated his lanthanium sample into two oxides; for one of these he retained the name lanthanum and for the other he gave the name didymium (or twin).
Lanthanum was discovered by Carl Gustaf Mosander, a Swedish chemist, in 1839. Mosander was searching for impurities he believed existed within samples of cerium. He treated cerium nitrate (Ce(NO3)3) with dilute nitric acid (HNO3) and found a new substance he named lanthana (La2O3). Roughly 0.0018% of the earth's crust is composed of lanthanum. Today, lanthanum is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements that can contain as much as 25% lanthanum.
From the Greek word lanthanein, to escape notice. Mosander in 1839 extracted lanthana from impure cerium nitrate and recognized the new element.
Lanthanum was isolated in relatively pure form in 1923. Iron exchange and solvent extraction techniques have led to much easier isolation of the so-called "rare-earth" elements.
Pure lanthanum is a silvery-white, soft metal that can be cut with a knife when freshly prepared. It tarnishes rapidly in air, forming oxide and hydroxide films, and reacts slowly with cold water but more rapidly when finely divided or heated.
Lanthanum is used in high-refractive-index optical glasses for camera lenses, microscopes, and other precision optics. Mixed rare-earth metal rich in lanthanum has been used in lighter flints and spark-producing alloys. Lanthanum-containing nickel-metal hydride battery alloys store hydrogen reversibly. Lanthanum compounds are also used in fluid catalytic cracking catalysts, ceramic capacitors and dielectric materials, phosphors, and as additives in tungsten electrodes and specialty steels.
Lanthanum is one of the rare earth elements used to make carbon arc lights which are used in the motion picture industry for studio lighting and projector lights. Lanthanum also makes up about 25% of Misch metal, a material that is used to make flints for lighters. Lanthana (La2O3) is used to make the glass used in camera lenses and in other special glasses.
Rare-earth compounds containing lanthanum are extensively used in carbon lighting applications, especially by the motion picture industry for studio lighting and projection. This application consumes about 25 percent of the rare-earth compounds produced. La2O3 improves the alkali resistance of glass, and is used in making special optical glasses. Small amounts of lanthanum, as an additive, can be used to produce nodular cast iron.
There is current interest in hydrogen sponge alloys containing lanthanum. These alloys take up to 400 times their own volume of hydrogen gas, and the process is reversible. Every time they take up the gas, heat energy is released; therefore these alloys have possibilities in an energy conservation system.
Isotopes in Earth/Planetary Science
Studies have shown that 138La (with a half-life of 1.06×1011 years) can be used along with 138Ce and 136Ce to measure time elapsed from a supernova explosion producing large numbers of neutrinos [415] T. Hayakawa, T. Shizuma, T. Kajino, K. Ogawa, H. Nakada. Am. Phys. Soc.77, (2008)..
Isotopes in Geochronology
138La decays to 138Ce and 138Ba, respectively, by beta decay with a half-life of 1.06×1011 years and by electron capture with a half-life of 1.56×1011 years. The isotope-amount ratio n(138Ce)/n(142Ce) has been used for dating rocks on long time scales (billions of years) and as a chemical tracer in geochemistry [416] T. Hayashi, M. Tanimizu, T. Tanaka. Precambrian Res.135, 345 (2004).. The increase in radiogenic 138Ba in rocks enriched in rare earth elements, such as allanite, enables one to determine the age of such rocks (Fig. IUPAC.57.1) [417] S. Nakai, H. Shimizu, A. Masuda. Nature320, 433 (1986)..
Isotopes Used as a Source of Radioactive Isotope(s)
139La is used for the production of the medical radioisotope 139Ce via the 139La (p, n) 139Ce reaction [418] H. Aglan, S. A. Kandil, H. A. Hanafi, M. A. Mousa, Z. A. Saleh. J. Radioanal. Nucl. Chem.280, 533 (2009)..
Lanthanum almost exclusively forms compounds in the +3 oxidation state. Lanthanum oxide (La₂O₃) is a basic oxide used in optical glass and ceramics and readily absorbs moisture and CO₂ from air. Lanthanum chloride (LaCl₃), lanthanum nitrate (La(NO₃)₃), and lanthanum carbonate (La₂(CO₃)₃) are common salts of the La³⁺ ion. Lanthanum hexaboride (LaB₆) is a refractory conductor valued as an electron-emission material. Lanthanum strontium manganite, often written La₁₋ₓSrₓMnO₃, is important in oxide electronics and solid oxide fuel-cell cathodes.
See more information at the Lanthanum compound page.
Metallic lanthanum dust and turnings are flammable, and the metal reacts with moisture to release hydrogen. Soluble lanthanum salts can irritate skin, eyes, and the respiratory tract and may disturb calcium-related biological processes at sufficient exposure. Lanthanum has no established essential biological role. Natural lanthanum is effectively stable; radiological risk normally comes from associated thorium or uranium in ores, not from lanthanum itself.
Lanthanum and its compounds have a low to moderate acute toxicity rating; therefore, care should be taken in handling them.
Lanthanum occurs dispersed in the crust with other rare-earth elements and is concentrated mainly in phosphate and carbonate minerals. Weathering releases La³⁺ into soils and waters, where it tends to bind strongly to clays, organic matter, phosphates, and carbonates rather than remain highly mobile. Mining and processing can increase local rare-earth, acid, fluoride, and radionuclide burdens, depending on ore type and waste management.
Lanthanum is obtained chiefly as a co-product of rare-earth mining and separation, especially from bastnäsite and monazite concentrates. Separation relies on solvent extraction or ion-exchange processes because neighboring rare earths have very similar chemistry. It is one of the more abundant and lower-cost rare earths, but supply depends on integrated rare-earth processing capacity and demand for other elements in the same ores. Recycling occurs in limited streams such as nickel-metal hydride batteries and some catalysts, while optical glass and ceramics are less commonly recovered for lanthanum content.
Lanthanum is found in rare-earth minerals such as cerite, monazite, allanite, and bastnasite. Monazite and bastnasite are principal ores in which lanthanum occurs in percentages up to 25 percent and 38 percent respectively. Misch metal, used in making lighter flints, contains about 25 percent lanthanum.
The availability of lanthanum and other rare earths has improved greatly in recent years. The metal can be produced by reducing the anhydrous fluoride with calcium.
Lanthanum is an odd-atomic-number heavy element made mainly by neutron-capture processes followed by radioactive decay in earlier generations of stars. It is far less abundant cosmically than iron-group elements but is measurable in the Sun, meteorites, and many old stars. Its abundance pattern helps distinguish slow and rapid neutron-capture contributions in stellar material.
- Lanthanum metal expands when it solidifies, an uncommon behavior among metals.
- The name comes from Greek lanthanein, meaning to lie hidden, because it was found concealed in cerium minerals.
- La³⁺ is diamagnetic because it has no 4f electrons.
- Lanthanum hexaboride cathodes can emit electrons efficiently at high temperature.
- Lanthanum carbonate is used as a phosphate binder in some medical applications.
प्रतिमा
गुणधर्म
भौतिक
- अणुत्रिज्या (अनुभवाधारित)
- 195 pm सर्व घटकांच्या अणुत्रिज्या (अनुभवाधारित) ची तुलना करा →
- सहसंयुजी त्रिज्या
- 207 pm सर्व घटकांच्या सहसंयुजी त्रिज्या ची तुलना करा →
- व्हॅन डर वाल्स त्रिज्या
- 240 pm सर्व घटकांच्या व्हॅन डर वाल्स त्रिज्या ची तुलना करा →
- धात्विक त्रिज्या
- 169 pm सर्व घटकांच्या धात्विक त्रिज्या ची तुलना करा →
- घनता
- 6150 kg/m³ सर्व घटकांच्या घनता ची तुलना करा →
- मोलर आयतन
- 0.0225 L/mol
- STP येथे अवस्था
- घन सर्व घटकांच्या STP येथे अवस्था ची तुलना करा →
- द्रवणांक
- 917.85 °C सर्व घटकांच्या द्रवणांक ची तुलना करा →
- उत्कलनांक
- 3463.85 °C सर्व घटकांच्या उत्कलनांक ची तुलना करा →
- उष्णता चालकता
- 13.4 W/(m·K) सर्व घटकांच्या उष्णता चालकता ची तुलना करा →
- विशिष्ट उष्माधारकता
- 0.195 J/(g·K) सर्व घटकांच्या विशिष्ट उष्माधारकता ची तुलना करा →
- मोलर उष्माधारकता
- 27.11 J/(mol·K) सर्व घटकांच्या मोलर उष्माधारकता ची तुलना करा →
- स्फटिक संरचना
- षट्कोणी निकट-संकुलित सर्व घटकांच्या स्फटिक संरचना ची तुलना करा →
रासायनिक
- विद्युतऋणता (पॉलिंग)
- 1.1 सर्व घटकांच्या विद्युतऋणता (पॉलिंग) ची तुलना करा →
- इलेक्ट्रॉन आसक्ती
- 0.47 eV
- आयनीकरण ऊर्जा (पहिली)
- 5.5769 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पहिली) ची तुलना करा →
- आयनीकरण ऊर्जा (दुसरी)
- 11.184999 eV सर्व घटकांच्या आयनीकरण ऊर्जा (दुसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (तिसरी)
- 19.177366 eV सर्व घटकांच्या आयनीकरण ऊर्जा (तिसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (चौथी)
- 49.950172 eV सर्व घटकांच्या आयनीकरण ऊर्जा (चौथी) ची तुलना करा →
- आयनीकरण ऊर्जा (पाचवी)
- 61.600212 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पाचवी) ची तुलना करा →
- ऑक्सिडीकरण अवस्था
- 0, +1, +2, +3 सर्व घटकांच्या ऑक्सिडीकरण अवस्था ची तुलना करा →
- संयुजा इलेक्ट्रॉन
- 3 सर्व घटकांच्या संयुजा इलेक्ट्रॉन ची तुलना करा →
- इलेक्ट्रॉन संरूपण
- [Xe] 6s2 5d1
उष्मागतिक
- द्रवण उष्मा
- 0.06425869 eV सर्व घटकांच्या द्रवण उष्मा ची तुलना करा →
- बाष्पीभवन उष्मा
- 4.145722 eV सर्व घटकांच्या बाष्पीभवन उष्मा ची तुलना करा →
- संप्लवन उष्मा
- 4.467016 eV
- अणूकरण उष्मा
- 4.467016 eV
- अणूकरण एन्थाल्पी
- 4.467016 eV
केंद्रकीय
- प्रोटॉन
- 57 सर्व घटकांच्या प्रोटॉन ची तुलना करा →
- न्यूट्रॉन
- 82 सर्व घटकांच्या न्यूट्रॉन ची तुलना करा →
- ज्ञात समस्थानिके
- 42 सर्व घटकांच्या ज्ञात समस्थानिके ची तुलना करा →
- स्थिर समस्थानिके
- 1 सर्व घटकांच्या स्थिर समस्थानिके ची तुलना करा →
- सर्वाधिक स्थिर समस्थानिक
- La-139
- शोधाचे वर्ष
- 1839
विपुलता
- विपुलता (पृथ्वीचे कवच)
- 39 mg/kg सर्व घटकांच्या विपुलता (पृथ्वीचे कवच) ची तुलना करा →
- विपुलता (महासागर)
- 3.4 × 10−6 mg/L सर्व घटकांच्या विपुलता (महासागर) ची तुलना करा →
स्फटिक संरचना
- जालक स्थिरांक a
- 375 pm
इलेक्ट्रॉन संरचना
- प्रत्येक कवचातील इलेक्ट्रॉन
- 2, 8, 18, 18, 9, 2 सर्व घटकांच्या प्रत्येक कवचातील इलेक्ट्रॉन ची तुलना करा →
ओळखचिन्हे
- CAS क्रमांक
- 7439-91-0 सर्व घटकांच्या CAS क्रमांक ची तुलना करा →
- टर्म चिन्ह
- 2D3/2
- InChI
- InChI=1S/La
- InChI की
- FZLIPJUXYLNCLC-UHFFFAOYSA-N
इलेक्ट्रॉन संरूपण मोजलेले
La: 5d¹ 6s²[Xe] 5d¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 5d¹ 6s²अणुप्रतिमान
समस्थानिकांमुळे न्यूट्रॉन संख्या, वस्तुमान आणि स्थैर्य बदलते — विद्युतदृष्ट्या उदासीन अणूचे इलेक्ट्रॉन संरूपण बदलत नाही.
योजनात्मक अणुप्रतिमान, प्रमाणानुसार नाही.
अणूची विशिष्ट ओळख
उत्सर्जन / शोषण वर्णपट
समस्थानिक वितरण
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य |
|---|---|---|---|
| 139 स्थिर | १३८.९०६३५६३ ± ०.०००००२४ | 99.9112% | स्थिर |
अवस्था / स्थिती
कारण: द्रवणांकापेक्षा (917.85 °C) 892.9 °C कमी
योजनात्मक, प्रमाणानुसार नाही
अवस्थांतर बिंदू
अवस्थांतर ऊर्जा
द्रवणांकावर 1 mol वितळवण्यासाठी आवश्यक ऊर्जा
उत्कलनांकावर 1 mol चे बाष्पीभवन करण्यासाठी आवश्यक ऊर्जा
संप्लवनांकावर 1 mol चे संप्लवन करण्यासाठी आवश्यक ऊर्जा
घनता
प्रमाणित परिस्थितीत
प्रमाणित परिस्थितीत
अणुवर्णपट
57 पैकी 10 दाखवले आहेत. आयनाच्या विद्युतभारानुसार चढत्या क्रमाने मांडलेले.
वर्णरेषांचा संग्रह ?
| आयन | विद्युतभार | एकूण वर्णरेषा | संक्रमण संभाव्यता | पातळ्यांची नामांकने |
|---|---|---|---|---|
| La I | 0 | 393 | 315 | 393 |
| La II | +1 | 273 | 84 | 273 |
| La III | +2 | 122 | 0 | 0 |
| La IV | +3 | 87 | 0 | 0 |
| La V | +4 | 42 | 0 | 0 |
ऊर्जा पातळ्यांचा संग्रह ?
| आयन | विद्युतभार | पातळ्या |
|---|---|---|
| La I | 0 | 343 |
| La II | +1 | 119 |
| La III | +2 | 42 |
| La IV | +3 | 52 |
| La V | +4 | 37 |
| La VI | +5 | 2 |
| La VII | +6 | 2 |
| La VIII | +7 | 2 |
| La IX | +8 | 2 |
| La X | +9 | 2 |
आयनिक त्रिज्या
| विद्युतभार | समन्वय | प्रचक्रण | त्रिज्या |
|---|---|---|---|
| +3 | 6 | उपलब्ध नाही | 103.2 pm |
| +3 | 7 | उपलब्ध नाही | 110.00000000000001 pm |
| +3 | 8 | उपलब्ध नाही | 115.99999999999999 pm |
| +3 | 9 | उपलब्ध नाही | 121.6 pm |
| +3 | 10 | उपलब्ध नाही | 127 pm |
| +3 | 12 | उपलब्ध नाही | 136 pm |
संयुगे
समस्थानिके (1)
Natural lanthanum is a mixture of two stable isotopes, 138La and 139La. Twenty three other radioactive isotopes are recognized.
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य | क्षय प्रकार | |
|---|---|---|---|---|---|
| 139 स्थिर | १३८.९०६३५६३ ± ०.०००००२४ | 99.9112% ± 0.0007% | स्थिर | stable |
विस्तारित गुणधर्म
सहसंयुजी त्रिज्या (विस्तारित)
- सहसंयुजी त्रिज्या (प्युक्को)
- 180 pm
- सहसंयुजी त्रिज्या (प्युक्को, दुहेरी बंध)
- 139 pm
- सहसंयुजी त्रिज्या (प्युक्को, तिहेरी बंध)
- 139 pm
व्हॅन डर वाल्स त्रिज्या
- Batsanov
- 250 pm
- Alvarez
- 298 pm
- UFF
- 352.2 pm
- MM3
- 278 pm
अणुत्रिज्या आणि धात्विक त्रिज्या
- अणुत्रिज्या (राह्म)
- 284 pm
- धात्विक त्रिज्या (C12)
- 187 pm
क्रमांकन मापनपट्ट्या
- Mendeleev
- 13
- Pettifor
- 33
- Glawe
- 32
विद्युतऋणता मापनपट्ट्या
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 3
ध्रुवणक्षमता आणि अपस्करण
- द्विध्रुव ध्रुवणक्षमता
- 215 a.u.
- द्विध्रुव ध्रुवणक्षमता (अनिश्चितता)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3730 Ha·Bohr6
रासायनिक आसक्ती
- प्रोटॉन आसक्ती
- 1013 kJ/mol
- वायूची क्षारकता
- 991.9 kJ/mol
मिडेमा प्राचल
- मिडेमा मोलर आयतन
- 22.55 cm3/mol
- मिडेमा इलेक्ट्रॉन घनता
- 2
पुरवठा जोखीम आणि अर्थकारण
- उत्पादनाचे केंद्रीकरण
- 97
- सापेक्ष पुरवठा जोखीम
- 10
- साठ्यांचे वितरण
- 50
- राजकीय स्थैर्य (प्रमुख उत्पादक)
- 24
- राजकीय स्थैर्य (सर्वाधिक साठे असलेला देश)
- 24
अवस्थांतरे आणि अपरूपे
| द्रवणांक | 1193.15 K |
| उत्कलनांक | 3737.15 K |
ऑक्सिडीकरण अवस्थांचे वर्ग
प्रगत संदर्भ माहिती
परिरक्षण स्थिरांक (13)
| n | कक्षिका | σ |
|---|---|---|
| 1 | s | 1.1317 |
| 2 | p | 4.2044 |
| 2 | s | 15.0466 |
| 3 | d | 13.9398 |
| 3 | p | 18.8604 |
| 3 | s | 19.0569 |
| 4 | d | 32.2748 |
| 4 | f | 55.64 |
| 4 | p | 29.2936 |
| 4 | s | 28.2036 |
स्फटिक त्रिज्यांचा तपशील (6)
| विद्युतभार | CN | प्रचक्रण | rcrystal (pm) | उत्पत्ती |
|---|---|---|---|---|
| 3 | VI | 117.2 | from r^3 vs V plots, | |
| 3 | VII | 124 | ||
| 3 | VIII | 130 | from r^3 vs V plots, | |
| 3 | IX | 135.6 | from r^3 vs V plots, | |
| 3 | X | 141 | ||
| 3 | XII | 150 | calculated, |
समस्थानिक क्षय प्रकार (64)
| समस्थानिक | मोड | तीव्रता |
|---|---|---|
| 116 | B+ | — |
| 116 | B+p | — |
| 116 | p | — |
| 117 | p | 100% |
| 117 | B+ | — |
| 117 | B+p | — |
| 118 | B+ | — |
| 118 | B+p | — |
| 119 | B+ | — |
| 120 | B+ | 100% |
क्ष-किरण प्रकीर्णन गुणक (711)
| ऊर्जा (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 3.31251 |
| 10.1152 | — | 3.28769 |
| 10.2317 | — | 3.26306 |
| 10.3496 | — | 3.23861 |
| 10.4688 | — | 3.20975 |
| 10.5894 | — | 3.15961 |
| 10.7114 | — | 3.11024 |
| 10.8348 | — | 3.06165 |
| 10.9596 | — | 3.01382 |
| 11.0859 | — | 2.96673 |
अतिरिक्त माहिती
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3.9×101 milligrams per kilogram
संदर्भ (1)
- [5] Lanthanum https://education.jlab.org/itselemental/ele057.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
3.4×10-6 milligrams per liter
संदर्भ (1)
- [5] Lanthanum https://education.jlab.org/itselemental/ele057.html
Sources
Sources of this element.
Lanthanum is found in rare-earth minerals such as cerite, monazite, allanite, and bastnasite. Monazite and bastnasite are principal ores in which lanthanum occurs in percentages up to 25 percent and 38 percent respectively. Misch metal, used in making lighter flints, contains about 25 percent lanthanum.
The availability of lanthanum and other rare earths has improved greatly in recent years. The metal can be produced by reducing the anhydrous fluoride with calcium.
संदर्भ (1)
- [6] Lanthanum https://periodic.lanl.gov/57.shtml
संदर्भ
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Lanthanum.
The element property data was retrieved from publications.