24
Cr
6
週期
4
d
個質子
電子
個中子
24
24
28
一般屬性
原子序數
24
標準原子質量
51.9961
品質編號
52
類別
過渡金屬
顏色
銀色
放射性
希臘文“顔色”
晶體結構
Body Centered Cubic
歷史
In 1797, Louis Nicolas Vauquelin received samples of crocoite ore.

In 1798, Vauquelin discovered that he could isolate metallic chromium by heating the oxide in a charcoal oven, making him the discoverer of the element.

Vauquelin was also able to detect traces of chromium in precious gemstones, such as ruby or emerald.
每個外殼的電子
2, 8, 13, 1
電子排布
[Ar] 3d5 4s1
Cr
Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago
物理性質
物態
固體
密度
7.15 g/cm3
熔點
2180.15 K | 1907 °C | 3464.6 °F
沸點
2944.15 K | 2671 °C | 4839.8 °F
熔化熱
20.5 kJ/mol
汽化熱
339 kJ/mol
比熱容
0.449 J/g·K
地殼豐度
0.014%
宇宙豐度
0.0015%
High
圖片來源: Wikimedia Commons (Alchemist-hp)
High purity chromium crystals, produced by chemical transport reaction through decomposition of chromium iodides, as well as a high purity chromium cube for comparison
CAS 編號
7440-47-3
Pubchem CID 編號
23976
原子性質
原子半徑
128 pm
共價半徑
139 pm
電負性
1.66 (鲍林标度)
電離電位
6.7665 eV
原子體積
7.23 cm3/mol
熱導率
0.937 W/cm·K
氧化態
-2, -1, 1, 2, 3, 4, 5, 6
應用
Chromium is used to harden steel, manufacture stainless steel, and form many useful alloys.

It is mostly used in plating to produce a hard, beautiful surface and to prevent corrosion.

The metal is also widely used as a catalyst.

Chromium compounds are valued as pigments for their vivid green, yellow, red and orange colors.
In larger amounts, chromium can be toxic and carcinogenic
同位素
穩定同位素
50Cr, 52Cr, 53Cr, 54Cr
不穩定同位素
42Cr, 43Cr, 44Cr, 45Cr, 46Cr, 47Cr, 48Cr, 49Cr, 51Cr, 55Cr, 56Cr, 57Cr, 58Cr, 59Cr, 60Cr, 61Cr, 62Cr, 63Cr, 64Cr, 65Cr, 66Cr, 67Cr