Cerium

  • cerium, 58ce
    cerium2.jpg
    cerium
    pronunciationm/ (seer-ee-əm)
    appearancesilvery white
    standard atomic weight ar, std(ce)140.116(1)[1]
    cerium 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


    ce

    th
    lanthanumceriumpraseodymium
    atomic number (z)58
    groupgroup n/a
    periodperiod 6
    blockf-block
    element category  lanthanide
    electron configuration[xe] 4f1 5d1 6s2[2]
    electrons per shell2, 8, 18, 19, 9, 2
    physical properties
    phase at stpsolid
    melting point1068 k ​(795 °c, ​1463 °f)
    boiling point3716 k ​(3443 °c, ​6229 °f)
    density (near r.t.)6.770 g/cm3
    when liquid (at m.p.)6.55 g/cm3
    heat of fusion5.46 kj/mol
    heat of vaporization398 kj/mol
    molar heat capacity26.94 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 1992 2194 2442 2754 3159 3705
    atomic properties
    oxidation states+1, +2, +3, +4 (a mildly basic oxide)
    electronegativitypauling scale: 1.12
    ionization energies
    • 1st: 534.4 kj/mol
    • 2nd: 1050 kj/mol
    • 3rd: 1949 kj/mol
    • (more)
    atomic radiusempirical: 181.8 pm
    covalent radius204±9 pm
    color lines in a spectral range
    spectral lines of cerium
    other properties
    natural occurrenceprimordial
    crystal structuredouble hexagonal close-packed (dhcp)
    double hexagonal close packed crystal structure for cerium

    β-ce
    crystal structureface-centered cubic (fcc)
    face-centered cubic crystal structure for cerium

    γ-ce
    speed of sound thin rod2100 m/s (at 20 °c)
    thermal expansionγ, poly: 6.3 µm/(m·k) (at r.t.)
    thermal conductivity11.3 w/(m·k)
    electrical resistivityβ, poly: 828 nΩ·m (at r.t.)
    magnetic orderingparamagnetic[3]
    magnetic susceptibility(β) +2450.0·10−6 cm3/mol (293 k)[4]
    young's modulusγ form: 33.6 gpa
    shear modulusγ form: 13.5 gpa
    bulk modulusγ form: 21.5 gpa
    poisson ratioγ form: 0.24
    mohs hardness2.5
    vickers hardness210–470 mpa
    brinell hardness186–412 mpa
    cas number7440-45-1
    history
    namingafter dwarf planet ceres, itself named after roman deity of agriculture ceres
    discoverymartin heinrich klaproth, jöns jakob berzelius, wilhelm hisinger (1803)
    first isolationcarl gustaf mosander (1838)
    main isotopes of cerium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    134ce syn 3.16 d ε 134la
    136ce 0.186% stable
    138ce 0.251% stable
    139ce syn 137.640 d ε 139la
    140ce 88.449% stable
    141ce syn 32.501 d β 141pr
    142ce 11.114% stable
    143ce syn 33.039 d β 143pr
    144ce syn 284.893 d β 144pr
    category category: cerium
    | references

    cerium is a chemical element with the symbol ce and atomic number 58. cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also exceptionally has a stable +4 state that does not oxidize water. it is also considered one of the rare-earth elements. cerium has no biological role in humans and is not very toxic.

    despite always occurring in combination with the other rare-earth elements in minerals such as those of the monazite and bastnäsite groups, cerium is easy to extract from its ores, as it can be distinguished among the lanthanides by its unique ability to be oxidized to the +4 state. it is the most common of the lanthanides, followed by neodymium, lanthanum, and praseodymium. it is the 26th-most abundant element, making up 66 ppm of the earth's crust, half as much as chlorine and five times as much as lead.

    cerium was the first of the lanthanides to be discovered, in bastnäs, sweden, by jöns jakob berzelius and wilhelm hisinger in 1803, and independently by martin heinrich klaproth in germany in the same year. in 1839 carl gustaf mosander became the first to isolate the metal. today, cerium and its compounds have a variety of uses: for example, cerium(iv) oxide is used to polish glass and is an important part of catalytic converters. cerium metal is used in ferrocerium lighters for its pyrophoric properties. cerium-doped yag phosphor is used in conjunction with blue light-emitting diodes to produce white light in most commercial white led light sources.

  • characteristics
  • chemistry
  • history
  • occurrence and production
  • applications
  • biological role and precautions
  • references
  • bibliography

Cerium, 58Ce
Cerium2.jpg
Cerium
Pronunciationm/ (SEER-ee-əm)
Appearancesilvery white
Standard atomic weight Ar, std(Ce)140.116(1)[1]
Cerium 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


Ce

Th
lanthanumceriumpraseodymium
Atomic number (Z)58
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron configuration[Xe] 4f1 5d1 6s2[2]
Electrons per shell2, 8, 18, 19, 9, 2
Physical properties
Phase at STPsolid
Melting point1068 K ​(795 °C, ​1463 °F)
Boiling point3716 K ​(3443 °C, ​6229 °F)
Density (near r.t.)6.770 g/cm3
when liquid (at m.p.)6.55 g/cm3
Heat of fusion5.46 kJ/mol
Heat of vaporization398 kJ/mol
Molar heat capacity26.94 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1992 2194 2442 2754 3159 3705
Atomic properties
Oxidation states+1, +2, +3, +4 (a mildly basic oxide)
ElectronegativityPauling scale: 1.12
Ionization energies
  • 1st: 534.4 kJ/mol
  • 2nd: 1050 kJ/mol
  • 3rd: 1949 kJ/mol
  • (more)
Atomic radiusempirical: 181.8 pm
Covalent radius204±9 pm
Color lines in a spectral range
Spectral lines of cerium
Other properties
Natural occurrenceprimordial
Crystal structuredouble hexagonal close-packed (dhcp)
Double hexagonal close packed crystal structure for cerium

β-Ce
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for cerium

γ-Ce
Speed of sound thin rod2100 m/s (at 20 °C)
Thermal expansionγ, poly: 6.3 µm/(m·K) (at r.t.)
Thermal conductivity11.3 W/(m·K)
Electrical resistivityβ, poly: 828 nΩ·m (at r.t.)
Magnetic orderingparamagnetic[3]
Magnetic susceptibility(β) +2450.0·10−6 cm3/mol (293 K)[4]
Young's modulusγ form: 33.6 GPa
Shear modulusγ form: 13.5 GPa
Bulk modulusγ form: 21.5 GPa
Poisson ratioγ form: 0.24
Mohs hardness2.5
Vickers hardness210–470 MPa
Brinell hardness186–412 MPa
CAS Number7440-45-1
History
Namingafter dwarf planet Ceres, itself named after Roman deity of agriculture Ceres
DiscoveryMartin Heinrich Klaproth, Jöns Jakob Berzelius, Wilhelm Hisinger (1803)
First isolationCarl Gustaf Mosander (1838)
Main isotopes of cerium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
134Ce syn 3.16 d ε 134La
136Ce 0.186% stable
138Ce 0.251% stable
139Ce syn 137.640 d ε 139La
140Ce 88.449% stable
141Ce syn 32.501 d β 141Pr
142Ce 11.114% stable
143Ce syn 33.039 d β 143Pr
144Ce syn 284.893 d β 144Pr
Category Category: Cerium
| references

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

Despite always occurring in combination with the other rare-earth elements in minerals such as those of the monazite and bastnäsite groups, cerium is easy to extract from its ores, as it can be distinguished among the lanthanides by its unique ability to be oxidized to the +4 state. It is the most common of the lanthanides, followed by neodymium, lanthanum, and praseodymium. It is the 26th-most abundant element, making up 66 ppm of the Earth's crust, half as much as chlorine and five times as much as lead.

Cerium was the first of the lanthanides to be discovered, in Bastnäs, Sweden, by Jöns Jakob Berzelius and Wilhelm Hisinger in 1803, and independently by Martin Heinrich Klaproth in Germany in the same year. In 1839 Carl Gustaf Mosander became the first to isolate the metal. Today, cerium and its compounds have a variety of uses: for example, cerium(IV) oxide is used to polish glass and is an important part of catalytic converters. Cerium metal is used in ferrocerium lighters for its pyrophoric properties. Cerium-doped YAG phosphor is used in conjunction with blue light-emitting diodes to produce white light in most commercial white LED light sources.