Name: Iodine, iodes means "violet"
Discovery: Iodine was discovered in 1811 by Bernard Courtois in France. Courtois often helped his father create sodium and potassium compounds. They would gather seaweed, burn it, and then soak it in water. Sulfuric acid would then be added in order to get the unwanted seaweed chemicals out of the mixture. After the water evaporated, they would be left with the compounds. Courtois discovered Iodine one day when he added too much sulfuric acid which created a beautiful release of violet vapor.
Description: When solid it looks metallic and has a grayish- black or violet-dark gray color. As a gas (because of sublimation Iodine never exists as a liquid) it has a violet color and a harsh, unpleasant odor.
Source: Salt mines contain some Iodine along with sea water but the main source is sea kelp. As kelp grows it takes Iodine out of the water. In order to collect the Iodine the sea kelp is harvested, dried and burned.
Uses: Iodine makes an excellent germ killer which links to its use in sanitation systems along with the creation of antiseptics and drugs. However it can also be used to make dyes, specialized soaps and photographic film. Chemists also use Iodine as a catalyst, a substance used to alter the speed of a chemical reaction
Biological role: As mentioned before Iodine kills bacteria and other pathogens. It is also very crucial in maintaining a healthy life. Iodine is implicated with the production of the thyroid hormones. People who do not maintain the proper level become ill with Goiter, the main symptom of which being the growth of a large lump in the base of the neck. A lack of Iodine is also the leading cause of mental retardation, deafness, mutism and paralysis. Because of this, many companies now support the manufacturing of iodized salt, when they add potassium iodide to the table salt. In high doses the element can be just as harmful. It can irritate and burn the skin. If ingested it can be very poisonous.
Atomic Number: 53
Atomic Symbol: I
Atomic Mass: 126.9045
Melting Point: 113.7 C
Boiling Point: 183 C
Number of Neutrons: 74
Crystal Structure: orthorhombic
Density: 4.94 g/mL