Lanthanum (La)
lanthanideSolid
표준 원자량
138.90547 u전자 배치
[Xe] 6s2 5d1녹는점
917.85 °C끓는점
3463.85 °C밀도
6150 kg/m³산화 상태
0, +1, +2, +3전기 음성도(Pauling)
1.1제1 이온화 에너지
5.5769 eV발견 연도
1839원자 반지름
195 pm상세 정보
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.
이미지
특성
물리적 특성
- 원자 반지름(경험값)
- 195 pm 모든 원소의 원자 반지름(경험값) 비교 →
- 공유 결합 반지름
- 207 pm 모든 원소의 공유 결합 반지름 비교 →
- 반데르발스 반지름
- 240 pm 모든 원소의 반데르발스 반지름 비교 →
- 금속 반지름
- 169 pm 모든 원소의 금속 반지름 비교 →
- 밀도
- 6150 kg/m³ 모든 원소의 밀도 비교 →
- 몰 부피
- 0.0225 L/mol
- STP에서의 상
- 고체 모든 원소의 STP에서의 상 비교 →
- 녹는점
- 917.85 °C 모든 원소의 녹는점 비교 →
- 끓는점
- 3463.85 °C 모든 원소의 끓는점 비교 →
- 열전도율
- 13.4 W/(m·K) 모든 원소의 열전도율 비교 →
- 비열
- 0.195 J/(g·K) 모든 원소의 비열 비교 →
- 몰 열용량
- 27.11 J/(mol·K) 모든 원소의 몰 열용량 비교 →
- 결정 구조
- 육방 조밀 충전 모든 원소의 결정 구조 비교 →
화학적 특성
- 전기 음성도(Pauling)
- 1.1 모든 원소의 전기 음성도(Pauling) 비교 →
- 전자 친화도
- 0.47 eV
- 제1 이온화 에너지
- 5.5769 eV 모든 원소의 제1 이온화 에너지 비교 →
- 제2 이온화 에너지
- 11.184999 eV 모든 원소의 제2 이온화 에너지 비교 →
- 제3 이온화 에너지
- 19.177366 eV 모든 원소의 제3 이온화 에너지 비교 →
- 제4 이온화 에너지
- 49.950172 eV 모든 원소의 제4 이온화 에너지 비교 →
- 제5 이온화 에너지
- 61.600212 eV 모든 원소의 제5 이온화 에너지 비교 →
- 산화 상태
- 0, +1, +2, +3 모든 원소의 산화 상태 비교 →
- 원자가 전자
- 3 모든 원소의 원자가 전자 비교 →
- 전자 배치
- [Xe] 6s2 5d1
열역학적 특성
- 융해열
- 0.06425869 eV 모든 원소의 융해열 비교 →
- 기화열
- 4.145722 eV 모든 원소의 기화열 비교 →
- 승화열
- 4.467016 eV
- 원자화열
- 4.467016 eV
- 원자화 엔탈피
- 4.467016 eV
핵 특성
- 양성자 수
- 57 모든 원소의 양성자 수 비교 →
- 중성자 수
- 82 모든 원소의 중성자 수 비교 →
- 알려진 동위원소 수
- 42 모든 원소의 알려진 동위원소 수 비교 →
- 안정 동위원소 수
- 1 모든 원소의 안정 동위원소 수 비교 →
- 가장 안정한 동위원소
- La-139
- 발견 연도
- 1839
존재비
- 존재비(지각)
- 39 mg/kg 모든 원소의 존재비(지각) 비교 →
- 존재비(해양)
- 3.4 × 10−6 mg/L 모든 원소의 존재비(해양) 비교 →
결정 구조
- 격자 상수 a
- 375 pm
전자 구조
- 전자껍질별 전자 수
- 2, 8, 18, 18, 9, 2 모든 원소의 전자껍질별 전자 수 비교 →
식별자
- CAS 등록 번호
- 7439-91-0 모든 원소의 CAS 등록 번호 비교 →
- 항 기호
- 2D3/2
- InChI
- InChI=1S/La
- InChI 키
- FZLIPJUXYLNCLC-UHFFFAOYSA-N
전자 배치 측정값
La: 5d¹ 6s²[Xe] 5d¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 5d¹ 6s²원자 모형
동위원소에 따라 중성자 수, 질량, 안정성은 달라지지만, 중성 원자의 전자 배치는 달라지지 않습니다.
개략적인 원자 모형이며 실제 비율과 다릅니다.
원자 지문
방출 / 흡수 스펙트럼
동위원소 분포
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 |
|---|---|---|---|
| 139 안정 | 138.9063563 ± 0.0000024 | 99.9112% | 안정 |
상 / 상태
이유: 녹는점(917.85 °C)보다 892.9 °C 낮음
개략도이며 실제 비율과 다름
상전이점
전이 에너지
녹는점에서 1 mol을 녹이는 데 필요한 에너지
끓는점에서 1 mol을 기화시키는 데 필요한 에너지
승화점에서 1 mol을 승화시키는 데 필요한 에너지
밀도
표준 조건에서
표준 조건에서
원자 스펙트럼
전체 57개 중 10개를 표시합니다. 이온 전하순으로 정렬되었습니다(오름차순).
보유 스펙트럼선 데이터 ?
| 이온 | 전하 | 총 스펙트럼선 수 | 전이 확률 | 준위 표기 |
|---|---|---|---|---|
| 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 |
보유 에너지 준위 데이터 ?
| 이온 | 전하 | 준위 |
|---|---|---|
| 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 |
이온 반지름
| 전하 | 배위 | 스핀 | 반지름 |
|---|---|---|---|
| +3 | 6 | 해당 없음 | 103.2 pm |
| +3 | 7 | 해당 없음 | 110.00000000000001 pm |
| +3 | 8 | 해당 없음 | 115.99999999999999 pm |
| +3 | 9 | 해당 없음 | 121.6 pm |
| +3 | 10 | 해당 없음 | 127 pm |
| +3 | 12 | 해당 없음 | 136 pm |
화합물
동위원소 (1)
Natural lanthanum is a mixture of two stable isotopes, 138La and 139La. Twenty three other radioactive isotopes are recognized.
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 | 붕괴 방식 | |
|---|---|---|---|---|---|
| 139 안정 | 138.9063563 ± 0.0000024 | 99.9112% ± 0.0007% | 안정 | stable |
확장 특성
공유 결합 반지름(확장)
- 공유 결합 반지름(Pyykkö)
- 180 pm
- 공유 결합 반지름(Pyykkö, 이중 결합)
- 139 pm
- 공유 결합 반지름(Pyykkö, 삼중 결합)
- 139 pm
반데르발스 반지름
- Batsanov
- 250 pm
- Alvarez
- 298 pm
- UFF
- 352.2 pm
- MM3
- 278 pm
원자 및 금속 반지름
- 원자 반지름(Rahm)
- 284 pm
- 금속 반지름(C12)
- 187 pm
번호 척도
- Mendeleev
- 13
- Pettifor
- 33
- Glawe
- 32
전기 음성도 척도
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 3
분극률 및 분산
- 쌍극자 분극률
- 215 a.u.
- 쌍극자 분극률(불확도)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3730 Ha·Bohr6
화학 친화력
- 양성자 친화도
- 1013 kJ/mol
- 기체상 염기성
- 991.9 kJ/mol
미데마 매개변수
- 미데마 몰 부피
- 22.55 cm3/mol
- 미데마 전자 밀도
- 2
공급 위험 및 경제성
- 생산 집중도
- 97
- 상대적 공급 위험
- 10
- 매장량 분포
- 50
- 정치적 안정성(최대 생산국)
- 24
- 정치적 안정성(최대 매장국)
- 24
상전이 및 동소체
| 녹는점 | 1193.15 K |
| 끓는점 | 3737.15 K |
산화 상태 분류
심화 참고 데이터
차폐 상수 (13)
| n | 오비탈 | 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 |
결정 반지름 상세 정보 (6)
| 전하 | CN | 스핀 | rcrystal (pm) | 기원 |
|---|---|---|---|---|
| 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, |
동위원소 붕괴 방식 (64)
| 동위원소 | 모드 | 세기 |
|---|---|---|
| 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% |
X선 산란 인자 (711)
| 에너지 (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 |
추가 데이터
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3.9×101 milligrams per kilogram
참고 문헌 (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
참고 문헌 (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.
참고 문헌 (1)
- [6] Lanthanum https://periodic.lanl.gov/57.shtml
참고 문헌
(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.