Iodine is rare in nature, ranking 47th in the earth's crust. Except for the high content in seawater (50 ~ 60 micrograms per liter of seawater), the content in most soils, rocks and water is very low.
The source of iodine in nature mainly exists in the form of sodium iodate NaIO3 in Chilean saltpeter mine. The content of iodine in seawater is very small, but some marine organisms (such as seaweed and kelp) have the ability to selectively absorb and enrich iodine, which is an important source of iodine.
Extended data:
Uses of iodine:
1, iodine deficiency can lead to iodine deficiency and affect the thyroid gland, so people with insufficient iodine intake in their daily diet should eat iodized salt (sodium iodide, potassium iodide, or potassium iodate)?
2. Iodine tincture (also known as iodine, iodine alcohol solution) is an emergency disinfectant. ?
3. Photographic film contains potassium iodide. ?
The filament in the electric lamp contains tungsten iodide. ?
5. Nitrogen iodide is an explosive. ?
5. Iodine will turn blue when it meets starch, which can verify the existence of starch. ?
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