Lanthan

57
La
Gruppe
n/a
Periode
6
Block
f
Protonen
Elektronen
Neutronen
57
57
82
Generelle Eigenschaften
Ordnungszahl
57
Atommasse
138,90547
Massenzahl
139
Kategorie
Lanthanoide
Farbe
Silber
Radioaktiv
Nein
From the Greek word lanthanein, to lie hidden
Kristallstruktur
Einfach hexagonal
Geschichte
Lanthanum was discovered in 1839 by Swedish chemist Carl Gustav Mosander.

He partially decomposed a sample of cerium nitrate by heating and treating the resulting salt with dilute nitric acid.

From the resulting solution, he obtained a pale brick colored oxide of the new rare earth.

Lanthanum was isolated in relatively pure form in 1923.
Elektronen pro Schale
2, 8, 18, 18, 9, 2
Elektronenkonfiguration
[Xe] 5d1 6s2
La
Lanthanum is the most reactive of the rare earth metals
Physikalische Eigenschaften
Aggregatzustand
Fest
Dichte
6,145 g/cm3
Schmelzpunkt
1193,15 K | 920 °C | 1688 °F
Siedepunkt
3737,15 K | 3464 °C | 6267,2 °F
Schmelzwärme
6,2 kJ/mol
Verdampfungswärme
400 kJ/mol
Spezifische Wärmekapazität
0,195 J/g·K
Häufigkeit in der Erdkruste
0,0034%
Häufigkeit im Universum
2×10-7%
Pure
Danksagungen für Bilder: Images-of-elements
Pure lanthanum
CAS-Nummer
7439-91-0
PubChem CID Number
23926
Atomeigenschaften
Atomradius
187 pm
Kovalenter Radius
207 pm
Elektronegativität
1,1 (Pauling-Skala)
Ionisierungsenergie
5,5769 eV
Molares Volumen
22,5 cm3/mol
Wärmeleitfähigkeit
0,135 W/cm·K
Oxidationszustände
2, 3
Anwendung
Lanthanum is used in large quantities in batteries for hybrid automobiles.

It is also used to make night vision goggles.

Small amounts of lanthanum, as an additive, can be used to produce nodular cast iron.

Lanthanum carbonate is used to reduce blood levels of phosphate in patients with kidney disease.
Lanthanum and its compounds are considered to be moderately toxic
Isotope
Stabile Isotope
139La
Instabile Isotope
117La, 118La, 119La, 120La, 121La, 122La, 123La, 124La, 125La, 126La, 127La, 128La, 129La, 130La, 131La, 132La, 133La, 134La, 135La, 136La, 137La, 138La, 140La, 141La, 142La, 143La, 144La, 145La, 146La, 147La, 148La, 149La, 150La, 151La, 152La, 153La, 154La, 155La