77
Ir
9
週期
6
d
個質子
電子
個中子
77
77
115
一般屬性
原子序數
77
標準原子質量
192.217
品質編號
192
類別
過渡金屬
顏色
銀色
放射性
From the Latin word iris meaning rainbow
晶體結構
面居中立方
歷史
Iridium was discovered in 1803 by English chemist Smithson Tennant in London.

Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue.

Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal.
每個外殼的電子
2, 8, 18, 32, 15, 2
電子排布
[Xe] 4f14 5d7 6s2
Ir
Iridium is the most corrosion-resistant metal known
物理性質
物態
固體
密度
22.56 g/cm3
熔點
2739.15 K | 2466 °C | 4470.8 °F
沸點
4701.15 K | 4428 °C | 8002.4 °F
熔化熱
26 kJ/mol
汽化熱
560 kJ/mol
比熱容
0.131 J/g·K
地殼豐度
4×10-8%
宇宙豐度
2×10-7%
Pieces
圖片來源: Images-of-elements
Pieces of pure iridium
CAS 編號
7439-88-5
Pubchem CID 編號
23924
原子性質
原子半徑
136 pm
共價半徑
141 pm
電負性
2.2 (鲍林标度)
電離電位
8.967 eV
原子體積
8.54 cm3/mol
熱導率
1.47 W/cm·K
氧化態
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
應用
Iridium is used in making crucibles and other equipment that is used at high temperatures.

Iridium is also used as a hardening agent in platinum alloys.

Its resistance to arc erosion makes iridium alloys ideal for electrical contacts for spark plugs.

Radioactive isotopes of iridium are used in radiation therapy for the treatment of cancer.
Iridium is considered to be of low toxicity
同位素
穩定同位素
191Ir, 193Ir
不穩定同位素
164Ir, 165Ir, 166Ir, 167Ir, 168Ir, 169Ir, 170Ir, 171Ir, 172Ir, 173Ir, 174Ir, 175Ir, 176Ir, 177Ir, 178Ir, 179Ir, 180Ir, 181Ir, 182Ir, 183Ir, 184Ir, 185Ir, 186Ir, 187Ir, 188Ir, 189Ir, 190Ir, 192Ir, 194Ir, 195Ir, 196Ir, 197Ir, 198Ir, 199Ir