Europium

Symbol	Eu
Atomnummer	63
Gruppe	-
Periode	6
Blok	f
Klassifikation	Lanthanider

Udseende	-
Farve	Sølv

Antal protoner	63 p+
Antal neutroner	89 n0
Antal elektroner	63 e-

Fra Wikipedia, den gratis encyklopædiEuropium (opkaldt efter Europa) er det 63. grundstof i det periodiske system, og har det kemiske symbol Eu: Under normale temperatur- og trykforhold optræder dette lanthanid som et forholdsvis blødt (omtrent som bly), sølvhvidt metal der hurtigt iltes ("ruster"). Europium er det mest reaktionsvillige lanthanid, og angribes øjeblikkeligt af atmosfærisk luft: Ved temperaturer mellem 150 og 180 °C antændes stoffet spontant, og brænder med en rød flamme under dannelse af Europium(III)oxid (Eu2O3). Selv når det opbevares under mineralsk olie for at hindre luften adgang, ser man sjældent det rene, ikke-iltede metal. I forbindelse med vand danner det gas-formig brint og det svagt basiske europiumhydroxid.

Fase ved STP	Fast
Massefylde	5.264 g/cm3
Atommasse	151.964 u

Smeltepunkt	1099 K 825.85 °C 1518.53 °F
Kogepunkt	1802 K 1528.85 °C 2783.93 °F
Fordampningsvarme	175.73 kJ/mol

Elektronegativitet (Pauling Scale)	1.2
Elektronaffinitet	11.2 kJ/mol
Oxidationstrin	0, +2, +3 (a mildly basic oxide)
Ioniseringsenergier	547.1 kJ/mol 1085 kJ/mol 2404 kJ/mol 4120 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Xe] 4f7 6s2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f7 5s2 5p6 6s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f7 5s2 5p6 6s2
Elektroner pr. Skal	2, 8, 18, 25, 8, 2
Outer shell electrons	2
Valency-elektroner	3
Bohrs atommodel	Figur: Skaldiagram af Europium (Eu) atom.
Orbital diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 6s

Opdaget	Eugène-Anatole Demarçay (1896)
Første isolation	Eugène-Anatole Demarçay (1901)
Opdagelse af europium Although europium is present in most of the minerals containing the other rare elements, due to the difficulties in separating the elements it was not until the late 1800s that the element was isolated. William Crookes observed the phosphorescent spectra of the rare elements including those eventually assigned to europium. Europium was first found in 1892 by Paul Émile Lecoq de Boisbaudran, who obtained basic fractions from samarium-gadolinium concentrates which had spectral lines not accounted for by samarium or gadolinium. However, the discovery of europium is generally credited to French chemist Eugène-Anatole Demarçay, who suspected samples of the recently discovered element samarium were contaminated with an unknown element in 1896 and who was able to isolate it in 1901; he then named it europium.

Original word	Europe
Language of origin	Greek
Name source	Sted
Meaning	“Europe”
Naming The name is derived from Europe, the continent, chosen as a counterpart to americium which had been named after the Americas.

CAS Number	7440-53-1
ChemSpider ID	22417
EC number	231-161-7
PubChem CID Number	23981