53
I
17
週期
5
p
個質子
電子
個中子
53
53
74
一般屬性
原子序數
53
標準原子質量
126.90447
品質編號
127
類別
鹵素
顏色
板岩灰
放射性
From the Greek word iodes, violet
晶體結構
Base Centered Orthorhombic
歷史
Iodine was discovered by French chemist Bernard Courtois in 1811.

He treated the liquor obtained from the extraction of kelp, with sulfuric acid to produce a vapour with a violet color.

In 1812, Joseph Louis Gay-Lussac demonstrated that iodine was an element and its chemical relationship to chlorine.
每個外殼的電子
2, 8, 18, 18, 7
電子排布
[Kr] 4d10 5s2 5p5
I
Kelp was the main source of natural iodine in the 18th and 19th centuries
物理性質
物態
固體
密度
4.93 g/cm3
熔點
386.85 K | 113.7 °C | 236.66 °F
沸點
457.4 K | 184.25 °C | 363.65 °F
熔化熱
7.76 kJ/mol
汽化熱
20.9 kJ/mol
比熱容
0.214 J/g·K
地殼豐度
0.000049%
宇宙豐度
1×10-7%
Pure
圖片來源: Images-of-elements
Pure crystalline iodine
CAS 編號
7553-56-2
Pubchem CID 編號
807
原子性質
原子半徑
140 pm
共價半徑
139 pm
電負性
2.66 (鲍林标度)
電離電位
10.4513 eV
原子體積
25.74 cm3/mol
熱導率
0.00449 W/cm·K
氧化態
-1, 1, 3, 5, 7
應用
Iodine compounds are important in organic chemistry and very useful in medicine.

A solution containing potassium iodide and iodine in alcohol is used to disinfect external wounds.

Silver iodide is a major ingredient to traditional photographic film.

Iodine is added to table salt to prevent thyroid disease.
Elemental iodine is toxic if taken orally
同位素
穩定同位素
127I
不穩定同位素
108I, 109I, 110I, 111I, 112I, 113I, 114I, 115I, 116I, 117I, 118I, 119I, 120I, 121I, 122I, 123I, 124I, 125I, 126I, 128I, 129I, 130I, 131I, 132I, 133I, 134I, 135I, 136I, 137I, 138I, 139I, 140I, 141I, 142I, 143I, 144I