Lantan
57
La
Grupă
n/a
Perioadă
6
Bloc
f
Protoni
Electroni
Neutroni
57
57
82
Proprietăți Generale
Număr atomic
57
Masă atomică
138,90547
Numar de masa
139
Categorie
Lantanide
Culoare
Argint
Radioactive
Nu
Din cuvântul grecesc lanthanein, ascuns
Structură cristalină
Sistemul Hexagonal
Istoric
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.
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.
Electroni pe nivelul de energie
2, 8, 18, 18, 9, 2
Configurație electronică
[Xe] 5d1 6s2
Lanthanum is the most reactive of the rare earth metals
Proprietăți Fizice
Fază
Solid
Densitate
6,145 g/cm3
Punct de topire
1193,15 K | 920 °C | 1688 °F
Punct de fierbere
3737,15 K | 3464 °C | 6267,2 °F
Energie de fuziune
6,2 kJ/mol
Energie de evaporare
400 kJ/mol
Căldură specifică
0,195 J/g·K
Abundența în scoarța Pământului
0,0034%
Abundența în Univers
2×10-7%
Numarul CAS
7439-91-0
Număr CID PubChem
23926
Proprietăți Atomice
Rază atomică
187 pm
Rază de covalență
207 pm
Electronegativitate
1,1 (Scara lui Pauling)
Potențial de ionizare
5,5769 eV
Volum molar
22,5 cm3/mol
Conductivitate termică
0,135 W/cm·K
Număr de oxidare
2, 3
Aplicații
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.
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
Izotopi
Izotopi stabili
139LaIzotopi instabili
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