Kombu, a type of sea vegetable that contains iodine.
Iodine is a nonmetallic chemical element with symbol I and atomic number 53. It is part of a group of elements known as halogens, which also includes fluorine, chlorine, and bromine. Like most of the heavier elements, it is quite rare in the universe, but it is found in seawater, algae, and some minerals. It is an essential trace mineral necessary for proper human nutrition, but it is toxic in its elemental form. Iodine has a number of useful applications, especially in medicine, and is a common reagent used in chemistry laboratories.
properties
iodized salt.
Iodine is a dark gray, lustrous solid with a slightly bluish tint. If heated, some melting occurs, but much of the substance turns directly into vapor, which is a deep violet color. The steam, when cooled, directly condenses back into small solid crystals. The element is only slightly soluble in water, but readily dissolves in many organic solvents such as ethanol, acetone, and chloroform.
Iodine is often used in medicine.
Like the other halogens, this element is an oxidizing agent, meaning it will accept electrons to form compounds, but it is a less powerful oxidizer than fluorine, chlorine, or bromine. Like these elements, it will form ionic compounds with metals by accepting an electron, giving a positively charged metal ion and a negatively charged iodide ion; an example is potassium iodide. It will also form covalent compounds with other nonmetals, including hydrogen and many organic substances.
Health
Iodine is often used in analytical chemistry.
Iodine is required by the thyroid gland, which produces a number of important hormones that contain the element. It is also essential for proper brain development in unborn children and young children. The recommended daily intake of iodine is usually measured in micrograms (mcg), or thousandths of a gram, and varies based on age and other factors. For example, children between the ages of one and eight should get about 90 mcg a day, and lactating women about 290. Good dietary sources of this element include fish and other shellfish, seaweed, bread, cereals, and cereals. dairy products.
An iodine deficiency test involves putting a small amount of tincture of iodine on the skin overnight and seeing if it is absorbed.
Iodine deficiency can be a problem in some parts of the world. It can manifest as goiter, a condition of the thyroid gland, and in growth retardation and poor intellectual development. People who live in regions deficient in this element can take an appropriate supplement. However, the element should not be ingested in its uncombined form, as it is toxic and corrosive; instead, it is usually given in the form of non-toxic iodide salts such as potassium iodide. They are sometimes added to table salt to make iodized salt.
applications
An iodine deficiency can affect the function of the thyroid gland, which produces hormones that regulate blood pressure, body temperature, heart rate, and body metabolism.
Many people are familiar with tincture of iodine, a brown solution of the element in alcohol, used in the medical field as a germicide or antiseptic. Its oxidizing properties make it effective in eliminating harmful microorganisms. A solution of the element in water, along with potassium iodide, which increases its solubility, is sometimes used as a disinfectant and for emergency purification of drinking water. In industry, one of the largest uses of iodine is the production of acetic acid from methanol. Other industrial uses include the production of iodized salt and the red dye, erythrosine, which is used as a food dye and in some colored inks.
In medicine, small amounts of a radioactive isotope of the element can be used as a tracer to check the function of the thyroid gland. It can also be used to treat thyroid cancer so that it is taken up by cancer cells instead of healthy cells. Radioactive iodine is also produced in nuclear tests and accidents, and if inhaled or ingested, it tends to accumulate in the thyroid, where it can cause damage or cancer. For this reason, in the event of an accident at a nuclear power plant, people nearby can be given potassium iodide tablets: they provide a safe way to absorb the non-radioactive form of the element to block the accumulation of the radioactive form. in the thyroid..
As a laboratory reagent, the element is often used in analytical chemistry. For example, it is used in a very sensitive chemical test for starch, as the two react to form a compound with a deep dark blue color. This test can be used to detect very small amounts of starch. Unsaturated fats can be combined with amounts of iodine that are proportional to the degree of unsaturation: the less saturated the fat, the more element you will consume. This forms the basis of the iodine value that can be given to fats.
manufacture
The element was first prepared in 1811 by Bernard Courtois, when he treated seaweed ash with sulfuric acid. He obtained purple vapor, which condensed into crystals. Today, most iodine comes from brine, which contains iodides, or from sodium iodate, which is present in a type of calcium carbonate rock called caliche.