 Discovery Information |
| Who:
Bernard Courtois
|
| When: 1804 |
| Where: France |
|
| Name Origin |
| Greek: iodes (violet). |
|
| Sources |
| Occurs on land and in the sea in sodium and potassium compounds. Although the element is actually quite rare, kelp and certain other plants have the ability to concentrate iodine, which helps introduce the element into the food chain as well as keeping its cost down. |
|
| Uses |
| Required in small amounts by humans. Once used as an antiseptic, but no longer due to its poisonous nature. Silver iodide is used in photography. Tungsten iodide is used to stabilise the filaments in light bulbs. Iodine-131 is used as a tracer in medicine. |
|
| Notes |
| It is an essential trace element; the thyroid hormones, thyroxine and triiodothyronine contain iodine. |
| Direct contact with skin can cause lesions, so it should be handled with care. Iodine vapor is very irritating to the eye and to mucous membranes. |
