There are several unique properties of iodine. Classified as a halogen, iodine has a non-metallic appearance that is dark gray and shining. It has a characteristic purple vapor, and it doesn't react well with other chemicals. It has antimicrobial properties which allow it to be used as a disinfectant. In addition, iodine is a necessary nutrient for good health.
Halogens are non-metal elements that include iodine, fluorine, chlorine, bromine, and astatine. The reactive properties of iodine are quite small, making it the least reactive halogen. Despite this, iodine is able to form compounds with several elements.
Sublimation is the process for converting solid iodine into a gas without passing through the liquid state. In the case of iodine, the vapor that is produced has a purple color. The process was observed by Bernard Courtois in 1811.
The limited reactive properties of iodine also hinder its ability to dissolve in solution. It is poorly soluble in water, but is somewhat soluble in carbon tetrachloride. It appears to be more responsive to non-polar, organic solvents than polar solvents.
Iodine is usually found in the air, land, and water. The most abundant source is the ocean. Iodine is mined in parts of Chile, Colorado, and New Mexico. Deposits are usually found in saturated salt water or oil brine, which is salt water mixed with oil. Overall, the total yearly production of iodine is approximately 13,000 tons.
Iodine usually ends up in soil that is used to grow plants. In addition, cattle and other animals will consume these plants and have iodine in their system. Any iodine in the water supply will generally vaporize and enter the atmosphere. Burning coal and fuel also adds iodine to the atmosphere. The vast majority of the air borne iodine comes from the oceans.
The properties of iodine are used for a number of applications including as a dietary supplement and as a chemical in photography. As a supplement, iodine is usually added to salt since iodine isn't produced by the body. In the form of silver iodine, it is used to develop film. Other applications which utilize the properties of iodine include water purification, in which iodine tablets are used to neutralize bacteria in drinking water.
Many of the properties of iodine are used to improve health. Several types of skin cleansers utilize iodine to disinfect wounds. Also, iodine is required for good thyroid health. Without it, the thyroid gland will stop functioning and may become enlarged.