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Cerium

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Cerium, ₅₈Ce

Cerium

Pronunciation

/ˈsɪəriəm/(SEER-ee-əm)

Appearance

sillery white

Standard atomic weightA_r, std(Ce)

7002140116000000000♠140.116(1)^[1]

Cerium in theperiodic cairt

Siller (element)

Mercur (element)

-
↑
Ce
↓
Th

lanthanum ←cerium →praseodymium

Atomic nummer(Z)

58

Element category

Electron confeeguration

[Xe] 4f¹ 5d¹ 6s²^[2]

Electrons per shell

2, 8, 18, 19, 9, 2

Pheesical properties

solit

1068 K(795 °C,1463 °F)

3716 K(3443 °C,6229 °F)

Density(near r.t.)

6.770 g/cm³

when liquid (at m.p.)

6.55 g/cm³

5.46 kJ/mol

Heat o vapourisation

398 kJ/mol

Molar heat capacity

26.94 J/(mol·K)

Vapour pressur

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 mildlybasic oxide)

Electronegativity

Pauling scale: 1.12

empirical:181.8 pm

Covalent radius

204±9 pm

Colour lines in a spectral range

Spectral lines o cerium

Ither properties

Naitural occurrence

Creestal structur

face-centred cubic (fcc)

Face-centered cubic creestal structur for cerium

Speed o soondthin rod

2100 m/s(at 20 °C)

Thermal expansion

(r.t.) (γ, poly) 6.3 µm/(m·K)

Thermal conductivity

11.3 W/(m·K)

Electrical resistivity

(r.t.) (β, poly) 828 n Ω·m

Magnetic orderin

paramagnetic^[3]

Young's modulus

(γ form) 33.6 GPa

(γ form) 13.5 GPa

(γ form) 21.5 GPa

(γ form) 0.24

2.5

Vickers haurdness

270 MPa

Brinell haurdness

412 MPa

7440-45-1

History

Namin

efter dwarf planetCeres, itsel named efter Roman deity o agriculturCeres

Martin Heinrich Klaproth,Jöns Jakob Berzelius,Wilhelm Hisinger(1803)

First isolation

Carl Gustaf Mosander(1839)

Mainisotopes o cerium

Isotope	Abundance	Hauf-life(t_1/2)	Decay mode	Product
¹³⁴Ce	syn	3.16 d	ε	¹³⁴La
¹³⁶Ce	0.185%	>3.8×10¹⁶ y	(β⁺β⁺)	¹³⁶Ba
¹³⁸Ce	0.251%	>1.5×10¹⁴ y	(β⁺β⁺)	¹³⁸Ba
¹³⁹Ce	syn	137.640 d	ε	¹³⁹La
¹⁴⁰Ce	88.450%	-	(SF)
¹⁴¹Ce	syn	32.501 d	β⁻	¹⁴¹Pr
¹⁴²Ce	11.114%	>5×10¹⁶ y	(β⁻β⁻)	¹⁴²Nd
¹⁴²Ce	11.114%	>5×10¹⁶ y	(α)	¹³⁸Ba
¹⁴⁴Ce	syn	284.893 d	β⁻	¹⁴⁴Pr

Decay modes in parentheses is predict, but hisna yet been observed

Cerium is achemical element wi seembol Ce anatomic nummer 58. It is a saft, silvery, ductile metal which easily oxidizes in air. Cerium wis named efter thedwarf planet Ceres (itsel named for theRoman goddess o agricultur). Cerium is the maist abundant o therare yird elements, makin up aboot 0.0046% o theYird's crust bi wicht. It is foond in a feck o minerals, the maist important beinmonazite anbastnasite. Thare a wheen o ommercial applications o cerium. Thay include catalysts, additives fur tae fuel tae reduceemissions an tae gless an enamels tae chynge thair colour.Cerium oxide is an important component o gless polishin pouders an phosphors uised in screens an fluorescent lamps. It is uised in the "flint" (actuallyferrocerium) olichters.

References

[eedit |edit soorce]

↑Meija, Juris; et al. (2016)."Atomic weights of the elements 2013 (IUPAC Technical Report)".Pure and Applied Chemistry.88 (3): 265–91.doi:10.1515/pac-2015-0305.
↑Ground levels and ionization energies for the neutral atoms, NIST
↑Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.

Theperiodic cairt o the elements

Alkaline yird metals

Transeetion elements

Ithernane-metals

Unkent chemical properties

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