90
Th
無法計量
週期
7
f
個質子
電子
個中子
90
90
142
一般屬性
原子序數
90
標準原子質量
232.03806
品質編號
232
類別
錒系元素
顏色
銀色
放射性
Named after Thor, Scandinavian god of war
晶體結構
面居中立方
歷史
Thorium was discovered by Jöns Jacob Berzelius in 1828, in Stockholm, Sweden.

Thorium was first observed to be radioactive in 1898, independently, by Polish-French physicist Marie Curie and German chemist Gerhard Carl Schmidt.

The crystal bar process was discovered by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925 to produce high-purity metallic thorium.
每個外殼的電子
2, 8, 18, 32, 18, 10, 2
電子排布
[Rn] 6d2 7s2
Th
Thorium fuel research is continuing in several countries including the USA and India
物理性質
物態
固體
密度
11.7 g/cm3
熔點
2115.15 K | 1842 °C | 3347.6 °F
沸點
5061.15 K | 4788 °C | 8650.4 °F
熔化熱
16 kJ/mol
汽化熱
530 kJ/mol
比熱容
0.113 J/g·K
地殼豐度
0.0006%
宇宙豐度
4×10-8%
The
圖片來源: Wikimedia Commons (NASA/ESA/JHU/R.Sankrit & W.Blair)
The Earth's thorium originated in the death throes of ancient stars
CAS 編號
7440-29-1
Pubchem CID 編號
23960
原子性質
原子半徑
179 pm
共價半徑
206 pm
電負性
1.3 (鲍林标度)
電離電位
6.3067 eV
原子體積
19.9 cm3/mol
熱導率
0.54 W/cm·K
氧化態
2, 3, 4
應用
Thorium is used to coat tungsten filaments in light bulbs.

It is also used in its oxide form in gas tungsten arc welding to increase the high-temperature strength of tungsten electrodes and improve arc stability.

Thorium-magnesium alloys are used in the aerospace industry for aircraft engines.
Thorium is highly radioactive
同位素
穩定同位素
232Th
不穩定同位素
209Th, 210Th, 211Th, 212Th, 213Th, 214Th, 215Th, 216Th, 217Th, 218Th, 219Th, 220Th, 221Th, 222Th, 223Th, 224Th, 225Th, 226Th, 227Th, 228Th, 229Th, 230Th, 231Th, 233Th, 234Th, 235Th, 236Th, 237Th, 238Th