56
Ba
2
週期
6
s
個質子
電子
個中子
56
56
81
一般屬性
原子序數
56
標準原子質量
137.327
品質編號
137
類別
鹼土金屬
顏色
銀色
放射性
From the Greek word barys, heavy
晶體結構
Body Centered Cubic
歷史
Barium was identified as a new element in 1774 by Carl Wilhelm Scheele.

Barium was first isolated by electrolysis of molten barium salts in 1808, by Sir Humphry Davy in England.

Robert Bunsen and Augustus Matthiessen obtained pure barium by electrolysis of a molten mixture of barium chloride and ammonium chloride.
每個外殼的電子
2, 8, 18, 18, 8, 2
電子排布
[Xe] 6s2
Ba
At low doses, barium acts as a muscle stimulant
物理性質
物態
固體
密度
3.594 g/cm3
熔點
1000.15 K | 727 °C | 1340.6 °F
沸點
2170.15 K | 1897 °C | 3446.6 °F
熔化熱
8 kJ/mol
汽化熱
140 kJ/mol
比熱容
0.204 J/g·K
地殼豐度
0.034%
宇宙豐度
1×10-6%
Barium
圖片來源: Images-of-elements
Barium with a grey oxide layer under argon
CAS 編號
7440-39-3
Pubchem CID 編號
5355457
原子性質
原子半徑
222 pm
共價半徑
215 pm
電負性
0.89 (鲍林标度)
電離電位
5.2117 eV
原子體積
39.24 cm3/mol
熱導率
0.184 W/cm·K
氧化態
2
應用
Barium is used as a flashed getter in vacuum tubes to remove the last traces of gases.

It is often used in barium-nickel alloys for spark plug wire.

Barium sulfate is important to the petroleum industry as a drilling fluid in oil and gas wells.

Barium is also used in medicine to detect abnormalities in the digestive system.
Water-soluble barium compounds are poisonous
同位素
穩定同位素
130Ba, 132Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba
不穩定同位素
114Ba, 115Ba, 116Ba, 117Ba, 118Ba, 119Ba, 120Ba, 121Ba, 122Ba, 123Ba, 124Ba, 125Ba, 126Ba, 127Ba, 128Ba, 129Ba, 131Ba, 133Ba, 139Ba, 140Ba, 141Ba, 142Ba, 143Ba, 144Ba, 145Ba, 146Ba, 147Ba, 148Ba, 149Ba, 150Ba, 151Ba, 152Ba, 153Ba