Lanthanum

57
La
Gruppe
n/a
Periode
6
Blok
f
Protons
Electrons
Neutrons
57
57
82
General Properties
Atomnummer
57
Atommasse
138,90547
Mass Number
139
Kategori
Lantanider
Farve
Silver
Radioactive
Nej
From the Greek word lanthanein, to lie hidden
Krystalstruktur
Simpel Hexagonal
History
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
Physical Properties
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
Abundance in Earth's crust
0,0034%
Abundance in Universe
2×10-7%
Pure
Billede akkrediteringer: Images-of-elements
Pure lanthanum
CAS Number
7439-91-0
PubChem CID Number
23926
Atomic Properties
Atomradius
187 pm
Kovalent radius
207 pm
Elektronegativitet
1,1 (Paulings skala)
Ionization Potential
5,5769 eV
Atomic Volume
22,5 cm3/mol
Varmeledningsevne
0,135 W/cm·K
Oxidationstrin
2, 3
Applications
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
Stable Isotopes
139La
Unstable Isotopes
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