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Uses for Halogens

Halogens are elements found in the second column from the right of the periodic table. They are referred to as Group 17 and include fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (At). All halogens have seven electrons in their outer shells. At room temperature, the halogens exist in all three states: solid, gaseous and liquid.

  1. The Facts

    • The word "halogen" means salt-forming and comes from "halos," meaning salt in Greek. Halogens are diatomic molecules (particles composed of two atoms) that are highly reactive. As a result of their reactivity, halogens are never found in their native form. Furthermore, halogens display chemical and physical properties that are similar to nonmetals, according to ChemistryExplained.com.

    Features

    • Halogens have relatively low boiling and melting points that are higher for those elements listed lower in the group. At room temperature, iodine is a solid, bromine is a liquid, and chlorine and fluorine are gases, according to ChemistryExplained.com. All halogens have color that increases in intensity as you proceed down through the group. Furthermore, they are all poor electrical and thermal conductors (in all phases).

    Fluorine Uses

    • Fluorine does not have many everyday uses as an element because of its highly reactive nature. It is, however, used in the manufacture of rocket fuels, because of the increased tendency of other materials to burn when it is present. Caryacademy.org reports that fluorine is most often used in fluorine compounds, notably including fluoride, particularly for toothpaste to prevent tooth decay. Fluorine was also used in the early production of chlorofluorocarbons (CFC), for cooling and refrigeration, aerosol sprays and cleaning agents, until it was discovered that CFCs were harmful to the ozone layer and new processes were developed.

    Chlorine Uses

    • Chlorine has a variety of uses as a purifier and a disinfectant. It is used to disinfect plastics, polymers, solvents, pharmaceuticals and agrochemicals. Furthermore, thingquest.org states that this element is used to purify water against microbiological infections. Chlorine can often be found as an ingredient in various household cleaning products.

    Bromine Uses

    • Bromine is used in fumigants, flameproofing agents, dyes, medicines and pesticides and in water purification. According to ChemistryExplained.com, bromine is also utilized as an inorganic compound in photography.

    Iodine Uses

    • Iodine is useful as a topical microbicide. It has also been added to halogen lamps to lengthen the life of the filament. Furthermore, iodine is necessary for the proper function of the thyroid gland in humans, according to ChemistryExplained.com, which also shares that iodine has proven useful as a disinfectant in water treatment and as a stain in chemistry experiments.

    Astatine Uses

    • All known astatine isotopes are radioactive. While chemists know very little about the chemical and physical properties of this element, they do predict that it has properties similar to iodine, according to ChemistryExplained.com

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