Lantanum

57
La
Golongan
n/a
Periode
6
Blok
f
Proton
Elektron
Neutron
57
57
82
Sifat Umum
Nomor atom
57
Massa atom
138,90547
Nomor massa
139
Kategori
Lantanida
Warna
Perak
Radioaktif
Tidak
From the Greek word lanthanein, to lie hidden
Struktur kristal
Segienam Sederhana
Sejarah
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.
Elektron per kulit
2, 8, 18, 18, 9, 2
Konfigurasi elektron
[Xe] 5d1 6s2
La
Lanthanum is the most reactive of the rare earth metals
Sifat Fisika
Fase
Solid
Kepadatan
6,145 g/cm3
Titik lebur
1193,15 K | 920 °C | 1688 °F
Titik didih
3737,15 K | 3464 °C | 6267,2 °F
Kalor peleburan
6,2 kJ/mol
Kalor penguapan
400 kJ/mol
Kapasitas kalor molar
0,195 J/g·K
Kelimpahan di kerak bumi
0,0034%
Kelimpahan di alam semesta
2×10-7%
Pure
Kredit Gambar: Images-of-elements
Pure lanthanum
Nomor CAS
7439-91-0
PubChem CID Number
23926
Sifat Atom
Jari-jari atom
187 pm
Jari-jari kovalen
207 pm
Elektronegativitas
1,1 (Skala Pauling)
Potensi Ionisasi
5,5769 eV
Volume atom
22,5 cm3/mol
Kondusivitas termal
0,135 W/cm·K
Bilangan oksidasi
2, 3
Aplikasi
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
Isotop
Isotop stabil
139La
Isotop tidak stabil
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