57
La
無法計量
週期
6
f
個質子
電子
個中子
57
57
82
一般屬性
原子序數
57
標準原子質量
138.90547
品質編號
139
類別
鑭系元素
顏色
銀色
放射性
From the Greek word lanthanein, to lie hidden
晶體結構
簡單六角形
歷史
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.
每個外殼的電子
2, 8, 18, 18, 9, 2
電子排布
[Xe] 5d1 6s2
La
Lanthanum is the most reactive of the rare earth metals
物理性質
物態
固體
密度
6.145 g/cm3
熔點
1193.15 K | 920 °C | 1688 °F
沸點
3737.15 K | 3464 °C | 6267.2 °F
熔化熱
6.2 kJ/mol
汽化熱
400 kJ/mol
比熱容
0.195 J/g·K
地殼豐度
0.0034%
宇宙豐度
2×10-7%
Pure
圖片來源: Images-of-elements
Pure lanthanum
CAS 編號
7439-91-0
Pubchem CID 編號
23926
原子性質
原子半徑
187 pm
共價半徑
207 pm
電負性
1.1 (鲍林标度)
電離電位
5.5769 eV
原子體積
22.5 cm3/mol
熱導率
0.135 W/cm·K
氧化態
2, 3
應用
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
同位素
穩定同位素
139La
不穩定同位素
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