20
Ca
2
週期
4
s
個質子
電子
個中子
20
20
20
一般屬性
原子序數
20
標準原子質量
40.078
品質編號
40
類別
鹼土金屬
顏色
銀色
放射性
From the Latin word calx, lime
晶體結構
面居中立方
歷史
Calcium was known as early as the first century when the Ancient Romans prepared lime as calcium oxide.

Calcium was first isolated by Sir Humphry Davy in 1808 when he electrolyzed a mixture of lime and mercuric oxide.

Davy was trying to isolate calcium; when he heard that Jöns Jakob Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself.
每個外殼的電子
2, 8, 8, 2
電子排布
[Ar] 4s2
Ca
The shell of an egg is made up of primarily calcium carbonate
物理性質
物態
固體
密度
1.54 g/cm3
熔點
1115.15 K | 842 °C | 1547.6 °F
沸點
1757.15 K | 1484 °C | 2703.2 °F
熔化熱
8.54 kJ/mol
汽化熱
155 kJ/mol
比熱容
0.647 J/g·K
地殼豐度
5%
宇宙豐度
0.007%
Pure
圖片來源: Wikimedia Commons (Matthias Zepper)
Pure calcium in a protective argon gas atmosphere
CAS 編號
7440-70-2
Pubchem CID 編號
5460341
原子性質
原子半徑
197 pm
共價半徑
176 pm
電負性
1.00 (鲍林标度)
電離電位
6.1132 eV
原子體積
29.9 cm3/mol
熱導率
2.01 W/cm·K
氧化態
1, 2
應用
Calcium is used to remove oxygen, sulfur and carbon from alloys.

It is also used as an alloying agent used in the production of aluminum, beryllium, copper, lead, and magnesium alloys.

Calcium is used as a reducing agent in the extraction of other metals, such as uranium, zirconium, and thorium.

Calcium carbonate is used in manufacturing cement and mortar, lime and limestone.
Calcium is considered to be non-toxic
同位素
穩定同位素
40Ca, 42Ca, 43Ca, 44Ca, 46Ca
不穩定同位素
34Ca, 35Ca, 36Ca, 37Ca, 38Ca, 39Ca, 41Ca, 45Ca, 47Ca, 48Ca, 49Ca, 50Ca, 51Ca, 52Ca, 53Ca, 54Ca, 55Ca, 56Ca, 57Ca