Lanthanum

57
La
Gruppe
n/a
Periode
6
Blok
f
Protoner
Elektroner
Neutroner
57
57
82
Generelle Egenskaber
Atomnummer
57
Atommasse
138,90547
Masseantal
139
Kategori
Lantanider
Farve
Sølv
Radioaktiv
Nej
From the Greek word lanthanein, to lie hidden
Krystalstruktur
Simpel Hexagonal
Historie
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.
Elektroner i hver skal
2, 8, 18, 18, 9, 2
Elektronkonfiguration
[Xe] 5d1 6s2
La
Lanthanum is the most reactive of the rare earth metals
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
6,145 g/cm3
Smeltepunkt
1193,15 K | 920 °C | 1688 °F
Kogepunkt
3737,15 K | 3464 °C | 6267,2 °F
Smeltevarme
6,2 kJ/mol
Fordampningsvarme
400 kJ/mol
Varmefylde
0,195 J/g·K
Forekomst i jordskorpen
0,0034%
Forekomst i universet
2×10-7%
Pure
Billede akkrediteringer: Images-of-elements
Pure lanthanum
CAS-nummer
7439-91-0
PubChem CID-nummer
23926
Atomare egenskaber
Atomradius
187 pm
Kovalent radius
207 pm
Elektronegativitet
1,1 (Paulings skala)
Ioniseringspotentiale
5,5769 eV
Atomvolumen
22,5 cm3/mol
Varmeledningsevne
0,135 W/cm·K
Oxidationstrin
2, 3
Anvendelser
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
Isotoper
Stabile isotoper
139La
Ustabile isotoper
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