Cerium (Ce)
lanthanideSolid
Standart Atom Ağırlığı
140,116 uElektron dizilimi
[Xe] 6s2 4f1 5d1Erime noktası
797,85 °CKaynama noktası
3423,85 °CYoğunluk
6770 kg/m³Yükseltgenme basamakları
+1, +2, +3, +4Elektronegatiflik (Pauling)
1,12İyonlaşma enerjisi (1.)
5,5386 eVKeşif yılı
1801Atom yarıçapı
185 pmAyrıntılar
Cerium is the first lanthanide by atomic number and one of the most abundant rare-earth elements in the crust. It is a reactive, electropositive metal whose chemistry is unusual among lanthanides because both Ce³⁺ and Ce⁴⁺ are accessible in ordinary compounds. This Ce³⁺/Ce⁴⁺ redox pair, especially in oxides, makes cerium important in catalysts, polishing materials, glass treatment, and oxygen-storage applications.
Cerium is especially interesting because of its variable electronic structure. The energy of the inner 4f level is nearly the same as that of the outer (valence) electrons, and only small amounts of energy are required to change the relative occupancy of these electronic levels. This gives rise to dual valency states.
For example, a volume change of about 10 percent occurs when cerium is subjected to high pressures or low temperatures. Cesium's valence appears to change from about 3 to 4 when it is cooled or compressed. The low temperature behavior of cerium is complex.
Cerium is an iron-gray lustrous metal. It is malleable, and oxidizes very readily at room temperature, especially in moist air. Except for europium, cerium is the most reactive of the rare-earth metals. It decomposes slowly in cold water and rapidly in hot water.
Alkali solutions and dilute and concentrated acids attack the metal rapidly. The pure metal is likely to ignite if scratched with a knife.
Ceric slats are orange red or yellowish; cerous salts are usually white.
The name derives from the planetoid Ceres, which was discovered by the Italian astronomer Giuseppe Piazzi in 1801 and named for Ceres, the Roman goddess of agriculture and harvest. Two years later, the element cerium was discovered by the German chemist Martin-Heinrich Klaproth, who called it ochroeite earth because of its yellow colour.
Cerium was independently discovered at the same time by the Swedish chemist Jöns Jacob Berzelius and the Swedish mineralogist Wilhelm von Hisinger, who called it ceria. It was first isolated in 1875 by the American mineralogist and chemist William Frances Hillebrand and the American chemist Thomas H. Norton.
Cerium was discovered by Jöns Jacob Berzelius and Wilhelm von Hisinger, Swedish chemists, and independently by Martin Heinrich Klaproth, a German chemist, in 1803. Cerium is the most abundant of the rare earth elements and makes up about 0.0046% of the earth's crust. Today, cerium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements.
Cerium was named for the asteroid Ceres, which was discovered in 1801. The element was discovered two years later in 1803 by Klaproth and by Berzelius and Hisinger. In 1875 Hillebrand and Norton prepared the metal.
Pure cerium is a soft, silvery-gray metal that tarnishes readily in air. Fresh surfaces are metallic and bright, but oxidation quickly dulls them. The metal is ductile at room temperature, relatively low-melting for a lanthanide, and reactive enough that small particles can ignite when heated or abraded.
Cerium is widely used as cerium dioxide, CeO₂, in glass polishing powders and as an oxygen-storage component in automotive catalytic converters. Cerium compounds decolorize glass by oxidizing iron impurities and can also impart ultraviolet absorption. Mischmetal, a rare-earth alloy rich in cerium, is used in lighter flints and spark-producing alloys. Cerium is also used in some aluminum, magnesium, and iron alloys, where small additions can modify microstructure and oxidation behavior.
Pure cerium will ignite if it is scratched with a sharp object, but can be safely used if combined with other materials. Cerium 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. Cerium is also a component of Misch metal, a material that is used to make flints for lighters. Cerium is also used as a catalyst to refine petroleum and as an alloying agent to make special metals.
Cerium oxide (Ce2O3 and CeO2) is a component of the walls of self cleaning ovens and of incandescent lantern mantles. Cerium oxide is also used to polish glass surfaces. Ceric sulfate (Ce(So4)2) is used in some chemical analysis processes. Other cerium compounds are used to make some types of glass as well as to remove color from glass.
Cerium is a component of misch metal, which is extensively used in the manufacture of pyrophoric alloys for cigarette lighters. While cerium is not radioactive, the impure commercial grade may contain traces of thorium, which is radioactive. The oxide is an important constituent of incandescent gas mantles and is emerging as a hydrocarbon catalyst in self cleaning ovens where it can be incorporated into oven walls to prevent the collection of cooking residues.
As ceric sulfate is used extensively as a volumetric oxidizing agent in quantitative analysis. Cerium compounds are used in the manufacture of glass, both as a component and as a decolorizer.
The oxide is finding increased use as a glass polishing agent instead of rouge, for it polishes much faster than rouge. Cerium, with other rare earths, is used in carbon-arc lighting, especially in the motion picture industry. It is also useful as a catalyst in petroleum refining and in metallurgical and nuclear applications.
Isotopes in Earth/Planetary Science
When combined, 138La– 138Ce and 147Sm– 143Nd are two decay systems that are useful for studying processes affecting the light-rare-earth elements (lanthanum, cerium, praseodymium, neodymium, and samarium) and the igneous evolution of the Moon and Earth because different igneous materials have different cerium isotopic compositions (Fig. IUPAC.58.1) and can be used in mass balance investigations [419] H. Tazoe, H. Obata, T. Gamo. J. Anal. At. Spectrom.22, 616 (2007)., [420] M. Tanimizu, T. Tanaka. Geochim. Cosmochim. Acta66, 4007 (2002)..
Isotopes in Geochronology
138Ce is a radiogenic isotope produced by decay of 138La, with a half-life of 1.06×1011 years, one of the longest clocks in geochronology. Thus, the isotope-amount ratio n(138Ce)/n(142Ce) can be used for dating rocks on long time scales (billions of years) and can also be used as a chemical tracer in geochemical studies.
Isotopes in Medicine
144Ce (with a half-life of 0.78 year) has been used for brachytherapy applications in cells and vessels of the body. The half-life and specific activity of 144Ce give it a potential advantage over the commonly used isotope 192Ir of higher dose rate at shorter distances and lower irradiation of organs outside the tumor [424] V. O. Zilio, O. P. Joneja, Y. Popowski, F. O. Bochud, R. Chawla. Int. J. Radiat. Oncol. Biol. Phys.62, 585 (2005).. 144Ce enables the treatment of larger arteries as compared with 32P, another isotope commonly used for this style of radiotherapy.
Cerium commonly forms trivalent salts containing Ce³⁺ and tetravalent compounds containing Ce⁴⁺. Cerium dioxide, CeO₂, is the most important oxide and can reversibly lose small amounts of oxygen to form nonstoichiometric oxides, a property central to catalysis. Cerium(III) oxide, Ce₂O₃, is stable under reducing conditions. Cerium(III) chloride, CeCl₃, and cerium(III) nitrate, Ce(NO₃)₃, are common starting materials, while ceric ammonium nitrate, (NH₄)₂Ce(NO₃)₆, is a strong one-electron oxidant in laboratory chemistry.
See more information at the Cerium compound page.
Bulk cerium metal has low acute toxicity but is a fire risk as powder, turnings, or dust. It reacts with acids to release H₂ and should be kept from strong oxidizers and moisture when finely divided. Soluble cerium salts can irritate skin, eyes, and the respiratory tract, and inhalation of rare-earth dusts is an occupational concern. Natural cerium is not significantly radioactive for normal handling purposes.
Cerium occurs mainly in rare-earth minerals such as monazite, bastnäsite, and allanite, usually with other lanthanides. In surface environments it is commonly trivalent, but oxidation to Ce⁴⁺ can immobilize it as sparingly soluble oxides and hydroxides. This redox behavior produces cerium anomalies in marine sediments and some rocks, which are used as geochemical indicators of oxidation conditions.
Cerium is obtained as a by-product of rare-earth mining and separation, especially from bastnäsite and monazite concentrates. Because it is relatively abundant compared with many rare earths, supply is often tied more to separation capacity and demand for the whole rare-earth suite than to geological scarcity. Major demand comes from polishing powders, catalysts, glass additives, and pyrophoric alloys. Recycling is limited but possible from spent catalysts and industrial polishing slurries when collection and contamination levels make recovery practical.
Cerium is the most abundant so-called rare-earth metals. It is found in a number of minerals including allanite (also known as orthite), monazite, bastnasite, cerite, and samarskite. Monazite and bastnasite are presently the more important sources of cerium.
Large deposits of monazite (found on the beaches of Travancore, India and in river sands in Brazil), allanite (in the western United States), and bastnasite (in Southern California) will supply cerium, thorium, and the other rare-earth metals for many years to come.
Metallic cerium is prepared by metallothermic reduction techniques, such as reducing cerous fluoride with calcium, or using electrolysis of molten cerous chloride or others processes. The metallothermic technique produces high-purity cerium.
Cerium is made chiefly by neutron-capture processes in evolved stars, including the slow s-process and rapid r-process contributions. It is far less abundant cosmically than iron or oxygen but is one of the more abundant lanthanides. Cerium has been detected spectroscopically in some chemically peculiar stars, where rare-earth lines can be unusually strong.
- Cerium was named after the dwarf planet Ceres, discovered shortly before the element.
- CeO₂ can store and release oxygen without fully changing its crystal framework.
- Cerium is the only lanthanide with a common, stable tetravalent aqueous and solid-state chemistry.
- Finely divided cerium-rich alloys are the sparking material in many lighter flints.
- Cerium can show geochemical anomalies because Ce³⁺ is oxidized more readily than neighboring lanthanides.
Görseller
Özellikler
Fiziksel
- Atom yarıçapı (ampirik)
- 185 pm Tüm elementlerin Atom yarıçapı (ampirik) değerlerini karşılaştır →
- Kovalent yarıçap
- 204 pm Tüm elementlerin Kovalent yarıçap değerlerini karşılaştır →
- Van der Waals yarıçapı
- 235 pm Tüm elementlerin Van der Waals yarıçapı değerlerini karşılaştır →
- Yoğunluk
- 6770 kg/m³ Tüm elementlerin Yoğunluk değerlerini karşılaştır →
- Molar hacim
- 0,021 L/mol
- STP'deki faz
- Katı Tüm elementlerin STP'deki faz değerlerini karşılaştır →
- Erime noktası
- 797,85 °C Tüm elementlerin Erime noktası değerlerini karşılaştır →
- Kaynama noktası
- 3423,85 °C Tüm elementlerin Kaynama noktası değerlerini karşılaştır →
- Isıl iletkenlik
- 11,3 W/(m·K) Tüm elementlerin Isıl iletkenlik değerlerini karşılaştır →
- Özgül ısı kapasitesi
- 0,192 J/(g·K) Tüm elementlerin Özgül ısı kapasitesi değerlerini karşılaştır →
- Molar ısı kapasitesi
- 26,94 J/(mol·K) Tüm elementlerin Molar ısı kapasitesi değerlerini karşılaştır →
- Kristal yapı
- Yüzey merkezli kübik Tüm elementlerin Kristal yapı değerlerini karşılaştır →
Kimyasal
- Elektronegatiflik (Pauling)
- 1,12 Tüm elementlerin Elektronegatiflik (Pauling) değerlerini karşılaştır →
- Elektron ilgisi
- 0,955 eV
- İyonlaşma enerjisi (1.)
- 5,5386 eV Tüm elementlerin İyonlaşma enerjisi (1.) değerlerini karşılaştır →
- İyonlaşma enerjisi (2.)
- 10,956038 eV Tüm elementlerin İyonlaşma enerjisi (2.) değerlerini karşılaştır →
- İyonlaşma enerjisi (3.)
- 20,19747 eV Tüm elementlerin İyonlaşma enerjisi (3.) değerlerini karşılaştır →
- İyonlaşma enerjisi (4.)
- 36,906127 eV Tüm elementlerin İyonlaşma enerjisi (4.) değerlerini karşılaştır →
- İyonlaşma enerjisi (5.)
- 65,550226 eV Tüm elementlerin İyonlaşma enerjisi (5.) değerlerini karşılaştır →
- Yükseltgenme basamakları
- +1, +2, +3, +4 Tüm elementlerin Yükseltgenme basamakları değerlerini karşılaştır →
- Değerlik elektronları
- 3 Tüm elementlerin Değerlik elektronları değerlerini karşılaştır →
- Elektron dizilimi
- [Xe] 6s2 4f1 5d1
Termodinamik
- Erime ısısı
- 0,05658911 eV Tüm elementlerin Erime ısısı değerlerini karşılaştır →
- Buharlaşma ısısı
- 3,254392 eV Tüm elementlerin Buharlaşma ısısı değerlerini karşılaştır →
- Süblimleşme ısısı
- 4,124994 eV
- Atomlaşma ısısı
- 4,124994 eV
- Atomlaşma entalpisi
- 4,354045 eV
Nükleer
- Protonlar
- 58 Tüm elementlerin Protonlar değerlerini karşılaştır →
- Nötronlar
- 82 Tüm elementlerin Nötronlar değerlerini karşılaştır →
- Bilinen izotoplar
- 41 Tüm elementlerin Bilinen izotoplar değerlerini karşılaştır →
- Kararlı izotoplar
- 1 Tüm elementlerin Kararlı izotoplar değerlerini karşılaştır →
- En kararlı izotop
- Ce-140
- Keşif yılı
- 1801
Bolluk
- Bolluk (yer kabuğu)
- 66,5 mg/kg Tüm elementlerin Bolluk (yer kabuğu) değerlerini karşılaştır →
- Bolluk (okyanus)
- 1,2 × 10−6 mg/L Tüm elementlerin Bolluk (okyanus) değerlerini karşılaştır →
Kristal Yapı
- Örgü sabiti a
- 516 pm
Elektronik Yapı
- Kabuk başına elektron sayısı
- 2, 8, 18, 19, 9, 2 Tüm elementlerin Kabuk başına elektron sayısı değerlerini karşılaştır →
Tanımlayıcılar
- CAS numarası
- 7440-45-1 Tüm elementlerin CAS numarası değerlerini karşılaştır →
- Terim simgesi
- 1G°4
- InChI
- InChI=1S/Ce
- InChI Anahtarı
- GWXLDORMOJMVQZ-UHFFFAOYSA-N
Elektron Dizilimi Ölçülmüş
Ce: 4f¹ 5d¹ 6s²[Xe] 4f¹ 5d¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹ 5d¹ 6s²Atom modeli
İzotoplar nötron sayısını, kütleyi ve kararlılığı değiştirir; nötr bir atomun elektron dizilimini değiştirmez.
Şematik atom modeli, ölçekli değildir.
Atomik Parmak İzi
Emisyon / Soğurma Spektrumu
İzotop Dağılımı
| Kütle numarası | Atom kütlesi (u) | Doğal bolluk | Yarı ömür |
|---|---|---|---|
| 140 Kararlı | 139,9054431 ± 0,0000023 | 88,4500% | Kararlı |
Faz / Hâl
Neden: erime noktasının (797,85 °C) 772,9 °C altında
Şematik, ölçekli değil
Faz geçiş noktaları
Geçiş enerjileri
Erime noktasında 1 mol maddeyi eritmek için gereken enerji
Kaynama noktasında 1 mol maddeyi buharlaştırmak için gereken enerji
Süblimleşme noktasında 1 mol maddeyi süblimleştirmek için gereken enerji
Yoğunluk
Standart koşullarda
Standart koşullarda
Atomik Spektrumlar
58 kayıttan 10 tanesi gösteriliyor. İyon yüküne göre sıralandı (artan).
Spektral Çizgi Kayıtları ?
| İyon | Yük | Toplam çizgi sayısı | Geçiş olasılıkları | Düzey gösterimleri |
|---|---|---|---|---|
| Ce I | 0 | 209 | 67 | 209 |
| Ce II | +1 | 560 | 283 | 560 |
| Ce III | +2 | 262 | 0 | 0 |
| Ce IV | +3 | 27 | 0 | 0 |
| Ce V | +4 | 5 | 0 | 0 |
Enerji Düzeyi Kayıtları ?
| İyon | Yük | Düzeyler |
|---|---|---|
| Ce I | 0 | 953 |
| Ce II | +1 | 491 |
| Ce III | +2 | 227 |
| Ce IV | +3 | 17 |
| Ce V | +4 | 12 |
| Ce VI | +5 | 4 |
| Ce VII | +6 | 2 |
| Ce VIII | +7 | 2 |
| Ce IX | +8 | 2 |
| Ce X | +9 | 2 |
İyon Yarıçapları
| Yük | Koordinasyon | Spin | Yarıçap |
|---|---|---|---|
| +3 | 6 | Mevcut değil | 101 pm |
| +3 | 7 | Mevcut değil | 107 pm |
| +3 | 8 | Mevcut değil | 114.3 pm |
| +3 | 9 | Mevcut değil | 119.6 pm |
| +3 | 10 | Mevcut değil | 125 pm |
| +3 | 12 | Mevcut değil | 134 pm |
| +4 | 6 | Mevcut değil | 87 pm |
| +4 | 8 | Mevcut değil | 97 pm |
| +4 | 10 | Mevcut değil | 97 pm |
| +4 | 12 | Mevcut değil | 113.99999999999999 pm |
Bileşikler
İzotoplar (1)
| Kütle numarası | Atom kütlesi (u) | Doğal bolluk | Yarı ömür | Bozunma türü | |
|---|---|---|---|---|---|
| 140 Kararlı | 139,9054431 ± 0,0000023 | 88,4500% ± 0,0510% | Kararlı | stable |
Genişletilmiş Özellikler
Kovalent Yarıçaplar (Genişletilmiş)
- Kovalent yarıçap (Pyykkö)
- 163 pm
- Kovalent yarıçap (Pyykkö, çift bağ)
- 137 pm
- Kovalent yarıçap (Pyykkö, üçlü bağ)
- 131 pm
Van der Waals Yarıçapları
- Alvarez
- 288 pm
- UFF
- 355,6 pm
- MM3
- 274 pm
Atom ve Metalik Yarıçaplar
- Atom yarıçapı (Rahm)
- 282 pm
Numaralandırma Ölçekleri
- Mendeleev
- 15
- Pettifor
- 32
- Glawe
- 31
Elektronegatiflik Ölçekleri
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 3
Kutuplanabilirlik ve Dispersiyon
- Dipol kutuplanabilirliği
- 205 a.u.
- Dipol kutuplanabilirliği (belirsizlik)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3480 Ha·Bohr6
Miedema Parametreleri
- Miedema molar hacmi
- 21,62 cm3/mol
- Miedema elektron yoğunluğu
- 2
Tedarik Riski ve Ekonomi
- Üretim yoğunlaşması
- 97
- Göreli tedarik riski
- 10
- Rezerv dağılımı
- 50
- Siyasi istikrar (en büyük üretici)
- 24
- Siyasi istikrar (en büyük rezerv sahibi)
- 24
Faz Geçişleri ve Allotroplar
| Erime noktası | 1072,15 K |
| Kaynama noktası | 3716,15 K |
Yükseltgenme Basamağı Kategorileri
İleri Düzey Referans Verileri
Perdeleme Sabitleri (13)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 1,1519 |
| 2 | p | 4,2176 |
| 2 | s | 15,26 |
| 3 | d | 13,9147 |
| 3 | p | 19,0405 |
| 3 | s | 19,3408 |
| 4 | d | 32,3392 |
| 4 | f | 56,324 |
| 4 | p | 29,3936 |
| 4 | s | 28,32 |
Kristal Yarıçaplarının Ayrıntıları (10)
| Yük | CN | Spin | rcrystal (pm) | Köken |
|---|---|---|---|---|
| 3 | VI | 115 | from r^3 vs V plots, | |
| 3 | VII | 121 | estimated, | |
| 3 | VIII | 128,3 | from r^3 vs V plots, | |
| 3 | IX | 133,6 | from r^3 vs V plots, | |
| 3 | X | 139 | ||
| 3 | XII | 148 | calculated, | |
| 4 | VI | 101 | from r^3 vs V plots, | |
| 4 | VIII | 111 | from r^3 vs V plots, | |
| 4 | X | 121 | from r^3 vs V plots, | |
| 4 | XII | 128 |
İzotop Bozunma Türleri (54)
| İzotop | Mod | Şiddet |
|---|---|---|
| 119 | B+ | — |
| 119 | B+p | — |
| 120 | B+ | — |
| 120 | B+p | — |
| 121 | B+ | 100% |
| 121 | B+p | 1% |
| 122 | B+ | — |
| 122 | B+p | — |
| 123 | B+ | 100% |
| 123 | B+p | — |
X Işını Saçılma Faktörleri (508)
| Enerji (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 1,28369 |
| 10,1617 | — | 1,26389 |
| 10,3261 | — | 1,24441 |
| 10,4931 | — | 1,22522 |
| 10,6628 | — | 1,20632 |
| 10,8353 | — | 1,18772 |
| 11,0106 | — | 1,16941 |
| 11,1886 | — | 1,15138 |
| 11,3696 | — | 1,13362 |
| 11,5535 | — | 1,11614 |
Ek Veriler
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
6.65×101 milligrams per kilogram
Kaynaklar (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.2×10-6 milligrams per liter
Kaynaklar (1)
Sources
Sources of this element.
Cerium is the most abundant so-called rare-earth metals. It is found in a number of minerals including allanite (also known as orthite), monazite, bastnasite, cerite, and samarskite. Monazite and bastnasite are presently the more important sources of cerium.
Large deposits of monazite (found on the beaches of Travancore, India and in river sands in Brazil), allanite (in the western United States), and bastnasite (in Southern California) will supply cerium, thorium, and the other rare-earth metals for many years to come.
Metallic cerium is prepared by metallothermic reduction techniques, such as reducing cerous fluoride with calcium, or using electrolysis of molten cerous chloride or others processes. The metallothermic technique produces high-purity cerium.
Kaynaklar (1)
- [6] Cerium https://periodic.lanl.gov/58.shtml
Kaynaklar
(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 Cerium.
The element property data was retrieved from publications.