Symbol	Ce
Atomnummer	58
Gruppe	-
Periode	6
Blok	f
Klassifikation	Lanthanider

Udseende	Silvery white
Farve	Sølv

Antal protoner	58 p+
Antal neutroner	82 n0
Antal elektroner	58 e-

Fra Wikipedia, den gratis encyklopædiCerium er det 58. grundstof i det periodiske system, og har det kemiske symbol Ce. Under normale temperatur- og trykforhold ligner dette metal jern, men det er langt blødere og mere formbart. Rent, metallisk cerium "anløbes" (iltes) hurtigt ved kontakt med atmosfærisk luft, og kan endda bryde i brand hvis man skraber i det med f.eks. en kniv. Cerium reagerer også villigt med syrer, baser og pH-neutralt vand, om end reaktionen med koldt vand forløber langsomt. Af alle de sjældne jordarter er det kun europium der er mere reaktionsvilligt end cerium.

Fase ved STP	Fast
Massefylde	6.77 g/cm3
Atommasse	140.116 u

Smeltepunkt	1068 K 794.85 °C 1462.73 °F
Kogepunkt	3716 K 3442.85 °C 6229.13 °F
Fordampningsvarme	313.8 kJ/mol

Elektronegativitet (Pauling Scale)	1.12
Elektronaffinitet	55 kJ/mol
Oxidationstrin	+1, +2, +3, +4 (a mildly basic oxide)
Ioniseringsenergier	534.4 kJ/mol 1050 kJ/mol 1949 kJ/mol 3547 kJ/mol 6325 kJ/mol 7490 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Xe] 4f1 5d1 6s2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f1 5s2 5p6 5d1 6s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f1 5s2 5p6 5d1 6s2
Elektroner pr. Skal	2, 8, 18, 19, 9, 2
Valenselektroner	2
Valency-elektroner	4
Bohrs atommodel	Figur: Skaldiagram af Cerium (Ce) atom.
Orbital diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 6s

Opdaget	Martin Heinrich Klaproth, Wilhelm Hisinger, Jöns Jacob Berzelius (1803)
Første isolation	Carl Gustaf Mosander (1838)
Navngivet af	Jöns Jacob Berzelius
Opdagelse af cerium Cerium was discovered in Bastnäs in Sweden by Jöns Jakob Berzelius and Wilhelm Hisinger, and independently in Germany by Martin Heinrich Klaproth, both in 1803. Cerium was named by Berzelius after the asteroid Ceres, discovered two years earlier. The asteroid is itself named after the Roman goddess Ceres, goddess of agriculture, grain crops, fertility and motherly relationships. Cerium was originally isolated in the form of its oxide, which was named ceria, a term that is still used. Ceria, as isolated in 1803, contained all of the lanthanides present in the cerite ore from Bastnäs, Sweden, and thus only contained about 45% of what is now known to be pure ceria. It was not until Carl Gustaf Mosander succeeded in removing lanthana and "didymia" in the late 1830s that ceria was obtained pure.

CAS Number	7440-45-1
ChemSpider ID	22411
EC number	231-154-9
PubChem CID Number	23974